Subluxation Index Research Articles

Humeral rotation osteotomy is not associated with glenohumeral and scapulohumeral decentering at long-term follow-up

BackgroundWeber rotational osteotomy which increases humeral retrotorsion in patients with anterior shoulder instability has become unpopular because of recurrence of instability and high rates of early onset OA. However, the wear pattern in patients after rotational osteotomy remains unknown. The aim of this study was to determine the influence of surgically increased humerus retrotorsion on glenohumeral and scapulohumeral centering in a long-term follow-up. MethodsThe data of 18 shoulders in 18 patients diagnosed with a unilateral chronic recurrent anterior shoulder instability treated with an internal rotation subcapital humerus osteotomy between 1984 and 1990 were drawn from a previously published cohort and enrolled in the study. All patients had available bilateral CT scans performed after a mean follow-up of 14 (12-18) years. On these CT scans a comparison of the operated and the contralateral healthy side with regards to humerus torsion, glenoid version, glenoid offset, glenohumeral and scapulohumeral subluxation indices, rotator cuff action lines and osteoarthritic changes (OA) was performed. ResultsThe analysis of follow-up CT scans revealed a significantly higher mean humeral retrotorsion in the operated side compared to healthy side (41.6° ± 14.0° vs. 20.7°±8.2°, p<0.001). No differences were found in terms of glenohumeral subluxation index (0.50 ± 0.08 vs 0.51 ± 0.03, p = 0.259), scapulohumeral subluxation index (0.53 ± 0.09 vs 0.54 ± 0.03, p = 0.283), glenoid version (- 3.9° ± 4.6 vs - 4.1° ± 3.7, p = 0.424), glenoid offset (4.0 mm ± 2.8 vs 4.0 mm ± 1.3, p = 0.484), infraspinatus action lines (102.5° ± 4.7 vs 101.2° ± 2.1, p = 0.116) , subscapularis action lines (74.0° ± 6.0 vs 73.1° ± 2.3, p = 0.260) and resultant rotator cuff action lines (87.8° ± 4.9 vs 87.0° ± 1.8, p = 0.231) between operated and healthy shoulders. Osteoarthritic changes were observed in all operated shoulders and in 13 of 18 healthy shoulders. The OA Grade was mild in 5 patients, moderate in 11 and severe in 2 cases for operated shoulders and mild in 13 healthy shoulders at the last follow-up. ConclusionThe surgical increase of humeral retrotorsion by 20-30° did not affect glenohumeral and scapulohumeral centering in patients with a Weber rotational osteotomy after a long-term follow-up compared to the healthy side. While a high degree of early onset OA was observed it remains unclear whether the cause is the surgical interventions performed or the joint instability itself.

Reference Values and influencing factors of the Glenohumeral Subluxation Index - a study on 3004 participants.

The primary objective of this study was to examine the Glenohumeral subluxation index (GHSI) in a large general population cohort and to define reference values. Glenohumeral subluxation is important in the development and prediction of pathological states of the shoulder joint and in total shoulder arthroplasty. Therefore, another objective was to examine the influence of age, sex, BMI, body height and weight on GHSI. GHSI according to Walch was measured on bilateral MRI of 3004 participants of the Study of Health in Pomerania (SHIP, aged 21-90 years). SHIP drew a sample of the adult general population of Pomerania (Northeastern Germany). Reference values for GHSI were assessed by quantile regression models. Associations of sex, age and anthropometric markers with the GHSI were calculated by linear regression models. A reference range between 42% and 55% for men with a mean of 49% ±4% was defined, while the upper reference limit of women was 1% higher (mean 50% ±4%). Age was inversely associated with the GHSI in males (p˂0.001), while no significant association in females was observed (p=0.625). Body weight and body mass index (BMI) was positively associated (p˂0.001) without effect modification by sex. Heavy mechanical oscillations on the upper extremity showed no significant association with GHSI (p = 0.268). The reference values for GHSI were expanded to a range of 42% - 57% on MRI. Several associations between GHSI and anthropometric properties are present. According to these associations, adjusted formulas are provided to enable individual, patient specific diagnostics and therapy. Nevertheless, the clinical picture cannot be neglected.

Three-dimensional evaluation of the transverse rotator cuff muscle's resultant force angle in relation to scapulohumeral subluxation and glenoid vault morphology in nonpathological shoulders

Static posterior subluxation of the humeral head (SPSH) results in glenohumeral osteoarthritis. Treatment strategies for SPSH with or without resulting osteoarthritis remain challenging. There is growing interest in evaluating the rotator cuff muscle volume, fatty infiltration, or forces in osteoarthritic shoulders with SPSH, mainly due to a possible transverse force imbalance. In nonpathological shoulders, the transverse angle of the rotator cuff muscle's resultant force may be associated with scapulohumeral alignment and glenoid vault morphology, despite an assumed transverse force balance. The purpose of this study was to assess the transverse rotator cuff muscle's resultant force angle (TRFA) and its relationship with the scapulohumeral subluxation index (SHSI) and selected glenoid vault parameters using computer modeling. Computed tomography scans of 55 trauma patients (age 31±13years, 36 males) with nonpathological shoulders were analyzed and all measurements performed in 3-dimension. We placed landmarks manually to determine the humeral head center and the rotator cuff tendon footprints. The contours of the rotator cuff muscle cross-sectional areas were automatically predicted in a plane perpendicular to the scapula. Each rotator cuff muscle was divided into virtual vector fibers with homogeneous density. The resultant force vector direction for each muscle, corresponding to the rotator cuff action line, was calculated by vectorially summing the normalized fiber vectors for each muscle, weighted by the muscle trophic ratio. The resultant force vector was projected on the axial plane, and its angle with the mediolateral scapular axis was used to determine TRFA. The SHSI according to Walch, glenoid version angle (GVA), glenoid anteroposterior offset angle (GOA), glenoid depth, glenoid width, and glenoid radius were also evaluated. The mean values for TRFA, SHSI, GVA, GOA, glenoid depth, glenoid width, and glenoid radius were 7.4±4.5°, 54.3±4.8%, -4.1±4.4°, 5.1±10.8°, 3.3±0.6mm, 20±2mm, and 33.6±4.6mm, respectively. The TRFA correlated strongly with SHSI (R=0.731, P<.001) and GVA (R=0.716, P<.001) and moderately with GOA (R=0.663, P<.001). The SHSI was strongly negatively correlated with GVA (R=-0.813, P<.001) and moderately with GOA (R=-0.552, P<.001). The GVA correlated strongly with GOA (R=0.768, P<.001). In contrast, TRFA, SHSI, GVA, and GOA did not correlate with glenoid depth, width, or radius. Despite an assumed balance in the transverse volume of the rotator cuff muscles in nonpathological shoulders, variations exist regarding the transverse resultant force depending on the SHSI, GVA, and GOA. In healthy/nonosteoarthritic shoulders, an increased glenoid retroversion is associated with a decreased anterior glenoid offset.

Pyrolytic carbon head shoulder arthroplasty: CT scan glenoid bone modeling assessment and clinical results at 3-year follow-up

The aim of this study is to report the radiological glenoid modifications and clinical outcomes at 3 years mean follow-up of hemi shoulder arthroplasty (HA) with pyrocarbon (PYC) humeral head. Our hypothesis was that the PYC implants would provide good outcomes without major glenoid erosion. Additionally, we hypothesized that HA-PYC allowed for remodeling of the bone. Patients underwent HA with PyC humeral head for treatment of primary or secondary osteoarthritis, excluding post-traumatic cases. All patients had a Constant Score assessed preoperatively and at the last follow-up. Preoperative and postoperative computed tomography scans at the last follow-up were performed to achieve 3-dimensional reconstructions of the scapulae. Deformities of the glenoid surface were analyzed as a distance differential between postoperative and preoperative to investigate potential bone remodeling vs. glenoid erosion. The subluxation index (SLI) was measured. We included 41 patients implanted with a HA-PYC. Average age at the time of implant was 63.8 (40 to 79 years). All patients were followed for ≥2 years with an average follow-up of 36.3 months (24 to 60 months). Constant Scores increased from 34 at baseline to 80 at the last follow-up points on average (P<.01). Return to work rate was 100% and 96% had resumed their physical activity. Ten (77%) of the 13 patients with posterior head subluxation had normalized their SLI. Furthermore, no significant differences were detected between the individuals having corrected their posterior subluxation and the others (preoperative SLI between 0.45 and 0.55). Glenoid wear is less than 0.6 mm at 3 years mean follow-up, ie, 5 times less than metallic implants. A tendency to recenter the head in the anteroposterior plane was found in type B glenoid, without increased erosion of the glenoid, with very good clinical results. We did not find any difference according to age or glenoid type for clinical and radiological results. HA-PYCs give, in the short term, excellent clinical results in terms of pain and function. The development of a precise and objective measurement method has made it possible to demonstrate that the glenoid surface is the site of modifications that may be part of bone remodeling or progression of the osteoarthritis disease.

Serial 3D CT analysis of humeral head alignment in relation to glenoid correction and outcomes after total shoulder arthroplasty

Posterior humeral head (HH) subluxation after anatomic total shoulder arthroplasty (aTSA) is associated with worse outcomes, but it is unclear how corrective glenoid reaming correlates with HH alignment and whether HH alignment changes over time. Therefore, it was aimed to analyze the relationship between HH alignment and the scapula following aTSA to identify anatomic andsurgical factors that contribute to realignment of the HH, glenoid loosening, and clinical outcomes. Three-dimensional scapulohumeral alignment was assessed on three-dimensionally reconstructed computed tomography scans of 23 patients: preoperative (T0), 2 years post-aTSA (T1), and ≥5 years post-aTSA (T2). Anterior-posterior (AP), superior-inferior (SI), and medial-lateral offset measures of the HH center to the scapula were referenced to the HH diameter (scapulohumeral subluxation index). Glenoid version and inclination were measured at T0 and T1. Central peg osteolysis, rotator cuff fatty infiltration, and vault perforation were assessed on two-dimensional computed tomography. Relative Constant Score at T2 measured clinical outcome. Glenoid correction correlated strongly with AP and SI position of the HH (r=0.733 and r=0.797, respectively). Each degree of retroversion correction resulted in 0.9% AP scapulohumeral subluxation index offset change toward anterior. Each degree of inclination correction to superior resulted in a 1.0% offset change toward superior. A gradual postoperative proximal (mean difference [MD],-3%; P=.019), anterior (MD, 2%; P=.025), and medial (MD, 3 mm; P<.001) HH migration was observed. Asymmetric progressive rotator cuff fatty infiltration was associated with the direction of change in AP alignment over time (odds ratio, 2.04; P=.046), with progressive subscapularis fatty infiltration as the primary factor associated with gradual anterior HH translation (odds ratio, 15.61; P=.028). Gradual HH medialization was an indicator of glenoid components at risk for loosening (difference between medians, 4 mm; P=.003). Osteolysis around the central glenoid peg was influenced by overcorrection of glenoid version (MD, 7°; P=.038). Preoperative glenoid inclination was the sole anatomical or surgical factor predicting clinical outcome, as larger inferior inclination at T0 was associated with worse relative Constant Score at T2 (P=.016). Corrective glenoid reaming was an effective surgical technique to correct HH alignment in the AP and SI direction. Gradual anterior HH translation after aTSA was associated with progressive subscapularis fatty infiltration, and substantial HH medialization was an important indicator for potential glenoid loosening. While postoperative glenoid version and AP HH alignment were important for radiographic outcome, preoperative glenoid inclination predicted clinical outcome, as larger preoperative inferior inclination resulted in worse clinical scores.

Arthroscopic Posterior Articular Coverage and Shift (PACS) Procedure for Treatment of Preosteoarthritic Constitutional Static Posterior Shoulder Instability (Type C1)

Background: Different joint-preserving techniques for treatment of preosteoarthritic, constitutional static (type C1) posterior shoulder instability (PSI) have been proposed, including posterior glenoid open wedge osteotomy and bone graft augmentation. However, the techniques are demanding, the reported complication and reoperation rates are high, and posterior decentering cannot reliably be reversed. Purpose: To assess the clinical and radiological longitudinal outcomes of patients with type C1 PSI after arthroscopic posterior articular coverage and shift (PACS) surgery. Study Design: Case series; Level of evidence, 4. Methods: We performed a retrospective analysis of a prospective database with longitudinal follow-up including 14 shoulders in 13 patients who underwent an arthroscopic PACS procedure for symptomatic preosteoarthritic constitutional static posterior instability (type C1) with previous failed nonoperative treatment. Patients were clinically evaluated before surgery and at 3, 6, 12, and 24 months postoperatively in terms of satisfaction and pain levels as well as standardized physical examination, Subjective Shoulder Value (SSV), Western Ontario Shoulder Instability Index (WOSI) score, Constant score, and Rowe score. Preoperative, postoperative, and follow-up magnetic resonance imaging scans were obtained in all patients. A paired 2-sample t test was used to compare changes in continuous variable parameters over time. Correlation analyses were performed using the Pearson correlation coefficient. Results: All outcome scores and the pain level improved significantly from preoperatively to postoperatively, and the improvement was sustained over the follow-up period of 2 years (pain level, 6.4 preoperatively vs 3.3 at 2 years, P < .001; SSV, 40 vs 70, P = .001; WOSI, 33 vs 56, P = .001; Constant, 70 vs 79, P = .049; Rowe, 52 vs 76, P < .001). The mean glenohumeral and scapulohumeral subluxation indices were significantly lower in the early postoperative period compared with preoperative measurements (glenohumeral, 52% ± 6% vs 58% ± 10%, P = .02; scapulohumeral, 70% ± 8%; vs 77% ± 9%, P = .002, respectively); however, they returned to baseline values at follow-up (57% ± 7% vs 58% ± 10%, P = .7; 75% ± 6% vs 77% ± 9%, P = .4, respectively). A high scapulohumeral subluxation index, excessive glenoid retroversion, and increased posterior positioning of the humeral head in relation to scapular blade axis and older age were correlated with worse clinical outcomes. Conclusion: Over the follow-up period of 2 years, the PACS procedure significantly improved outcome scores in patients who had preosteoarthritic constitutional static posterior shoulder instability, especially in younger patients with less severe glenoid retroversion and posterior decentering of the humeral head. However, similar to other techniques, the PACS procedure needs to be considered a symptomatic therapy that does not reverse the underlying cause or stop the progressive pathology.

Computed tomography revealed the correlation between radiolucency and alignment of all-polyethylene pegged glenoid component more than 10 years after total shoulder arthroplasty in the Japanese population

BackgroundAnatomical total shoulder arthroplasty (TSA) provides successful long-term outcomes but complications can occur after 10 years that require revision. Computed tomography (CT) is a useful tool for assessing radiolucent lines around the glenoid component of TSA; however, the merits of long-term post-TSA follow up with CT are unclear. The purpose of this study was to evaluate the long-term outcomes after TSA of Japanese population and to identify factors related to radiolucency around the glenoid component using CT. MethodsA retrospective review was conducted of TSA patients who had completed at least 10 years of clinical follow up. Radiographs and CT images of the affected shoulder obtained at the last follow up were evaluated for radiolucent lines around the stem and each peg, superior inclination and retroversion of the glenoid component, subluxation index, and critical shoulder angle (CSA). Shoulder ROM, Constant–Murley score and UCLA score were compared between the preoperative and last follow up period. ResultsEighteen shoulders in 16 patients met the inclusion criteria. Mean patient age was 61 years, mean follow up period was 137 months, and mean Yian CT score was 19%. CT score was significantly highest in pegs located inferiorly (p < 0.05). Mean glenoid superior inclination was 12.6°, retroversion was −0.3°, subluxation index was 46%, and CSA was 33.7°. Glenoid superior inclination was significantly lower (p = 0.007) in shoulders with possible loosening than in cases with no loosening (5.0° vs 15.6°). Mean Constant score and UCLA score improved significantly after TSA, from 25.8 to 10.7 points preoperatively to 70.1 and 28.9 points postoperatively, respectively. Mean shoulder flexion, internal rotation, and external rotation also showed improvement postoperatively. ConclusionTSA provides good long-term outcomes. Radiolucency was present most frequently around the inferior pegs of the glenoid component. Glenoid superior inclination may affect the formation of radiolucent lines around glenoid pegs. Level of evidenceLevel IV; Case Series; Treatment study.

Radiologic midterm results of cemented and uncemented glenoid components in primary osteoarthritis of the shoulder: a matched pair analysis.

Cemented all-polyethylene glenoid components are considered the gold standard in anatomic shoulder arthroplasty. New designs of cementless metal backed glenoid components showed promising early and midterm results. The aim of this matched-pair analysis was to compare the radiologic results of two cemented glenoid components and a cementless glenoid component in patients with primary osteoarthritis (OA). Sixty shoulders were clinically and radiologically evaluated after a mean follow-up of 59months. Mean patient age was 70.4years at surgery. Based on the design of the glenoid component (keel, peg, MB), 3 groups with, respectively, 20 shoulders were formed according to the matching criteria time of follow-up, patient age and gender. RLL and osteolysis in anteroposterior and axillary X-ray images were quantified and combined in a radiologic score (R-Score). Higher scores expressed worse radiologic outcomes. Further radiological parameters such as lateral glenohumeral offset (LGHO) and subluxation index were measured according to Walch. The functional results were documented using the age and gender normalized Constant-Murley score. Postoperative R-Score was highest in pegged components (peg: 5.7, keel: 2.4, MB: 1.6; p < 0.001) when combining both radiographs and after separate analysis of anteroposterior radiographs. MB glenoids had the lowest R-score in axillary radiographs (peg: 2.2, keel: 1.4, MB: 0.6; MB vs. keel: p = 0.004, MB vs peg: p < 0.001). RLL were more common (p = 0.004) and severe (p = 0.005) in pegged glenoids (RLL incidence: 77.8%, RLL-score: 2.5) than in MB glenoids (RLL incidence: 30%, RLL-score 0.7) and tended (p = 0.084) to have a higher RLL-score than keeled glenoids (RLL incidence: 63.2%, RLL-score:1.4). Both the osteolysis score (keel vs. peg: p < 0.001, MB vs. peg p < 0.001) and the incidence of osteolysis (keel vs. peg: p = 0.008, MB vs peg: p = 0.003) were significant higher in pegged glenoids (peg: osteolysis score: 3.2, osteolysis incidence: 100%; keel: osteolysis score: 1.0, osteolysis incidence: 63.2%, MB: osteolysis score: 0.9, osteolysis incidence: 60%), while the osteolysis score in axillary images was lowest for MB glenoids (peg: 1.2, keel: 0.9, MB: 0.4; peg vs. MB: p = 0.009, keel vs. MB: p = 0.047). Osteolysis in the central axillary zone was least common in MB glenoids (peg: 50%, keel: 47.4%, MB: 15%; peg vs. MB p = 0.035, keel vs. MB p = 0.041). LGHO was highest in MB glenoids (peg: 54.1, keel: 54.5, MB: 57.8; p < 0.001) but did not increase radiographic loosening (r = 0.007; p = 0.958). Preoperative posterior humeral head subluxation seemed to affect incidence of RLL negatively (pre-op posterior decentered 64.3%, pre-op centered 31.9%; p = 0.201) but did not reach statistical significance. Pegged glenoid components had a concerning rate of RLL and osteolysis. MB glenoid components had a better outcome in axillary radiographs concerning RLL and osteolysis. Increased LGHO did not increase radiographic loosening. Retrospective comperative treatment study Level III.

Abnormalities in distal first metatarsal joint surface orientation: Distal Metatarsal Articular Angle and Distal Metatarsal-2 Articular Angle

BackgroundHallux valgus (HV) in adults is an acquired pathology related to 1st metatarsal (M1) abduction. In children, it is related to abnormal M1 joint surface orientation. HypothesisHV deformities in children and adults differ. ObjectiveDescriptive study of radiologic abnormalities in a pediatric population of symptomatic HV, with comparison to a population without symptomatic HV. Materials and methodsWeight-bearing X-rays were studied in pediatric patients undergoing surgery for HV and in a control population. Measurements comprised M1P1, M1M2, DMAA, DM2AA, MPAA, and sesamoid subluxation index. ResultsTwenty-five patients (42 feet) were included in the HV group, and 16 patients (29 feet) in the control group. Mean age was 13 years in both. Interobserver reproducibility was excellent for M1P1, and good for M1M2, DMAA and DM2AA. In HV, 71% of feet showed M1M2 angle>12° and 98% DMAA>10°; DM2AA was>0°, except in 1 foot. DiscussionNormal values are the same in children and adults: M1P1<15°, DMAA<10° and M1M2<12°. In the HV group, DMAA was systematically pathological, while M1M2 was pathological in only 71% of cases. Childhood HV is related to abnormal DMAA, sometimes associated with increased M1M2 angle, especially in severe forms. DM2AA assesses distal M1 joint surface orientation with respect to the M2 axis; in the HV group, it was systematically>0° (except in 1 foot). Thus, in case of concomitant DMAA and M1M2 abnormalities, DMAA is more severely abnormal than M1M2 (DM2AA=DMAA-M1M2). ConclusionChildhood HV is mainly due to abnormal M1 joint surface orientation, sometimes associated with increased 1st metatarsal abduction. DM2AA reflects the balance between 1st metatarsal abduction and M1 joint surface orientation abnormality. Level of evidenceIII.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report.

Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. Level IV, therapeutic study.

만성 요통 환자의 골반 교정 운동이 척추부 변위 변화와 요통 장애 지수에 미치는 영향

이 연구는 부정렬 증후군을 동반한 만성 요통 환자를 대상으로 골반 교정 운동이 요통 장애 지수(ODI), 다리 길이 차이(LLD) 및 척추부 변위 변화에 어떠한 영향을 주는지를 밝히는데 그 목적이 있다. 연구의 대상은 부정렬 증후군을 동반한 만성 요통 환자 16명을 대상으로 운동군(EG, n=8), 통제군(CG, n=8)으로 분류하여 EG는 1회 60분, 주 3회, 12주간의 재활운동을 시행하였다. ODI, LLD 및 척추부 변위 변화(요추 전만각, 천골 경사각, 요추 너비, 천골 너비, 장골 길이 및 장골 너비)는 운동 전과 운동 12주 후 각각 측정하였다. ODI, LLD, 요추 전만각, 천골 경사각, 요추 너비, 천골 너비 및 장골 너비는 CG과 비교해서 EG에서 운동 후에 각각 유의하게 감소하였다(p.001). 이상의 결과, 이 연구에서 부정렬 증후군을 동반한 만성 요통환자의 골반 교정 운동은 ODI, LLD 및 척추부 변위 변화에 효과적인 사실을 증명하였다. 추후 만성 요통 환자를 위한 효율적인 운동방법으로 제시하고자하며 다른 관절부위에도 교정운동 프로그램 구성이 더 필요할 것으로 사료된다.

Glenoid vault and humeral head alignment in relation to the scapular blade axis in young patients with pre-osteoarthritic static posterior subluxation of the humeral head

Static posterior subluxation of the humeral head is a pre-osteoarthritic deformity preceding posterior erosion in young patients. Its etiology remains unknown. The aim of this study was to analyze the differences in scapular morphology between young patients with pre-osteoarthritic static posterior subluxation of the humeral head and healthy controls with a centered humeral head. We performed a retrospective analysis of all patients with pre-osteoarthritic static posterior subluxation of the humeral head who were treated in our institution between January 2018 and November 2019. Fourteen shoulders in 12 patients were included in this study and then matched according their age, sex, and affected side with controls. Computed tomography images of both groups were compared in the standardized axial imaging plane for differences in scapular morphology. The following parameters were measured: glenoid version relative to the Friedman line and scapular blade axis, scapulohumeral and glenohumeral subluxation index, and neck angle, as well as glenoidand humeral offset. The patients in the subluxation group showed significantly higher scapulohumeral and glenohumeral subluxation indexes than controls (0.76 vs. 0.55 [P < .0001] and 0.58 vs. 0.51 [P = .016], respectively). The mean measurements of glenoid version according to the Friedman line and relative to the scapular blade axis were significantly higher in the subluxation group than in controls (19° vs. 4° [P < .0001]and 14° vs. 2° [P = .0002], respectively). The glenoid vault was significantly more anteriorly positioned with respect to the scapular blade axis in the subluxation group than in controls (neck angle, 166° vs. 173° [P = .0003]; glenoid offset, 9.2 mm vs. 4.6 mm [P = .0005]). The midpoint of the humeral head showed a posterior offset with respect to the scapular blade axis in the subluxation group, whereas controls had an anteriorly placed midpoint of the humeral head (-2 mm vs. 3.1 mm, P = .01). A higher scapulohumeral subluxation index showed significant correlations with an increased anterior offset of the glenoid vault (increased glenoid offset: r = 0.493, P = .008 and decreased neck angle: r = -0.554, P = .002), a posterior humeral offset (r = -0.775, P < .0001), and excessive glenoid retroversion measured by both methods (Friedman line: r = 0.852, P < .0001; scapular blade axis: r = 0.803, P < .0001). A higher glenohumeral subluxation index also correlated significantly with an increased anterior offset of the glenoid vault (increased glenoid offset: r = 0.403, P = .034; decreased neck angle: r = -0.406, P = .032) and posterior humeral offset (r = -0.502, P = .006). Young patients with pre-osteoarthritic static posterior subluxation of the humeral head have significant constitutional differences in scapular morphology in terms of an increased anterior glenoid offset, excessive glenoid retroversion, and increased posterior humeral offset in relation to the scapular blade compared with healthy matched controls.

Prospective midterm results of a new convertible glenoid component in anatomic shoulder arthroplasty: a cohort study

The purpose of our study was to evaluate the clinical and radiological results of a new anatomic convertible cementless glenoid component. Forty-eight patients with a mean age of 67.3years were clinically and radiologically followed-up with a mean of 49months. Indications for glenoid replacement were A2 glenoid wear in 21.7%, B1 glenoid wear in 28.3%, B2 glenoid wear in 28.3%, B3 glenoid wear in 13%, D glenoid wear in 2.2%, and glenoid component loosening in 6.5%. The Constant-Murley score improved significantly (p < 0.0001) from 50% pre-OP to 103% post-OP. Patients with a B3 glenoid type according to Walch achieved a significant (p = 0.044) lower Constant-Murley Sscore post-OP compared to patients with a B1 glenoid type (88% vs 106%). The mean subluxation index changed significantly (p < 0.0001) from 0.54 pre-OP to 0.46 post-OP. At the metal-back bone interface an incomplete radiolucent line < 1mm was observed in two cases (4.2%) and an incomplete radiolucent line < 2mm was observed in another two cases (4.2%). PE dissociation occurred in two cases. No glenoid loosening was observed. The implant related revision rate was 4.2% (2 cases). All components (n = 612.5%) requiring conversion to reverse were converted without any further complications or loosening. Good functional results can be achieved in cases with a B1 and a B2 glenoid after anatomic shoulder arthroplasty using the described metal back glenoid. A conversion from an anatomic to a reverse glenoid component were possible in all cases without any further complications. Conversion of the anatomic glenoid component to a reverse system alleviates revision surgery.

Qualitative and quantitative analysis of glenoid bone stock and glenoid version: inter-reader analysis and correlation with rotator cuff tendinopathy and atrophy in patients with shoulder osteoarthritis.

Glenoid bone stock and morphology and rotator cuff muscle quality and tendon integrity affect the outcome of total shoulder arthroplasty. We hypothesized that glenoid bone loss correlates with rotator cuff muscle fatty infiltration (FI), tendinopathy, and atrophy. Forty-three 3D CT scans and MRIs of 43 patients (mean age 62years; SD 13years; range 22-77years) referred for primary shoulder pain were evaluated. Measurements of glenoid bone stock, version, and posterior humeral subluxation index (HSI) were assessed on an axial CT image reconstructed in the true scapular plane. Measurements utilized the Friedman line to approximate the pre-pathologic surface. Glenoid morphology was assigned by modified Walch classification. Rotator cuff FI, atrophy, and tendon integrity were assessed on corresponding MRIs. There was a very strong negative correlation between increasing glenoid version and HSI (r= - 0.908; p< 0.0001). There was a moderately negative correlation between anterior bone loss and HSI (r= - 0.562; p< 0.0001) and a moderately positive correlation between posterior bone loss and HSI (r= 0.555; p< 0.0001). Subscapularis muscle FI correlated moderately with increased anterior and central bone loss and increased humeral head medialization (r= 0.512, p= 0.0294; r= 0.479, p= 0.033; r= 0.494, p= 0.0294; respectively). Inter-observer reliability (intra-class correlation coefficient [ICC] and kappa) was good to excellent for all measurements and grading. Glenoid anteversion and anterior and posterior bone loss are associated with varying HSI. Subscapularis muscle FI, not tendon integrity, correlates to anterior and central glenoid erosion. The study adds evidence that neither rotator cuff tendinopathy nor muscle atrophy exhibits a significant relationship to HSI.

Influence of Anesthesia on Grading of Canine Hip Dysplasia

This study aimed to evaluate the effect of anesthesia on grading of canine hip dysplasia. For this purpose, 20 middle-sized healthy dogs from different breeds were used. Radiographs were taken using 4 different imaging methods, including the hip-extended, subluxation, distraction, and compression. This procedure was repeated 4 times for each dog, while the dogs were unanesthetized and anesthetized with 3 different anesthetic protocols at 15-day intervals (propofol [5 mg/kg, IV]; diazepam [0.5 mg/kg, IV] / ketamine [20 mg/kg, IV]; medetomidine [0.05 μg/kg, IM] / ketamine [20 mg/kg, IM]). The radiographs were taken and evaluated by the same investigator to prevent interobserver variation. Because of the radiographic positioning difficulty, unanesthetized radiographic imaging revealed higher repetition number than the anesthetized; therefore, radiation safety decreased. The administration of diazepam/ketamine and medetomidine/ketamine was sufficient in terms of both muscle relaxation and duration of the anesthesia; however, some dogs under propofol anesthesia were required maintenance doses to complete radiographic imaging procedure. Unanesthetized radiographic images of the dogs had significantly lower (P < .001) hip score, distraction index (DI), subluxation index (SI), and higher compression index (CI) (P< .001), when compared with anesthetized radiographic images. When compared the anesthetic protocols, propofol revealed lower (P< 0.001) hip score, DI, SI, and higher (P < .001) CI than medetomidine/ketamine. Medetomidine/ketamine is the most appropriate anesthetic protocol for detailed radiographic evaluation of CHD considering both muscle relaxation and duration of action.

Radiographic determination of humeroradial, humeroulnar, and radioulnar subluxation indices to quantify elbow incongruence in dogs confirmed to have medial coronoid disease

Medial coronoid disease and elbow incongruence are common orthopedic problems causing forelimb lameness in large breed dogs. Therefore, the objective of this retrospective clinical study is to radiographically quantify the incongruity of humeroradial, humeroulnar, and radioulnar joints in dogs with confirmed medial coronoid disease compared to controls. Sixty-six (93 elbows) control and 73 (113 elbows) diseased Labrador and Golden Retrievers were enrolled. Our objective was achieved by measuring the central humeroradial, humeroulnar, and radioulnar distances and calculating the corresponding subluxation index of each joint on the extended mediolateral elbow radiograph. The traditional radioulnar step was also measured on the same mediolateral projection. Variables were compared between control and diseased groups, and the significance level was P < .05. The central humeroradial, humeroulnar, and radioulnar distances and corresponding subluxation indices increased significantly (P ≤ .007) in elbows with confirmed medial coronoid disease compared to controls. Radioulnar step increased significantly (P < .0001) in diseased elbows. Elbow incongruence, manifested by increased humeroradial, humeroulnar, and radioulnar subluxation indices, appeared to be consistent with medial coronoid disease in Labrador and Golden Retrievers. An elbow with a humeroradial, humeroulnar, or radioulnar subluxation index >0.15, 0.10, or 0.14, respectively, or radioulnar step >1.4 mm, is more likely to be incongruent and may have a concomitant coronoid disease. However, future validation of the reported measurements is still warranted.

The CT dorsolateral subluxation index is a feasible method for quantifying laxity in the feline hip joint.

The dorsolateral subluxation index of the femoral head is a good proxy of hip dysplasia in dogs. An exploratory, prospective, descriptive study was carried out in order to assess whether the dorsolateral subluxation index may also be useful to improve diagnosis of hip dysplasia in cats. The dorsolateral subluxation index was determined by CT scans simulating the loading position, and compared with measurements of the Norberg-Olsson angle. A total of 82 cats were subjected to radiographic examination of the pelvis, in the standard ventro-dorsal projection, and to CT scans of the pelvis and hips. The Norberg-Olsson angle of each hip was calculated radiographically, while the dorsolateral subluxation index of the femur was calculated on CT images according to a technique recently developed for evaluation of hip dysplasia in dogs. Using the Norberg-Olsson angle a total of 52 hips (31,7%) were diagnosed as dysplastic, 74 (45,1%) as non-dysplastic, and 38 (23,1%) as borderline. Using the dorsolateral subluxation index, values ranged from a minimum of 34.6% to a maximum of 66.6% and four distribution classes were proposed. Findings indicated that the dorsolateral subluxation index previously described as method for quantifying hip dysplasia in dogs is also a feasible method for quantifying hip dysplasia in cats. Future studies are needed to more definitively determine the diagnostic sensitivity of this method.

Comparison of meniscal extrusion and osteophyte formation at the intercondylar notch as a predictive biomarker for incidence of knee osteoarthritis-Data from the Osteoarthritis Initiative-

BackgroundMedial meniscal extrusion (ME) is a biomarker to predict later development of knee osteoarthritis (KOA). On the other hand, we have reported osteophyte formation at the posterior condylar notch of the femur served as a biomarker for the same purpose. The purpose of this study is to compare capacity of the two biomarkers in predicting KOA development. MethodsTwo cohort of knees were established utilizing publicly available data from the Osteoarthritis Initiative (OAI). No OA group (NOA) consisted of knees that were grade 0 or 1 on Kellgren and Lawrence grade (K/L) both at baseline and 48 months later, and pre-radiographic-OA group (PROA) consisted of knees that were grade 0 or 1 at baseline but grade ≥2 48 months later. Baseline MR images were evaluated in terms of ME and osteophyte formation at the posterior condylar notch. ME was evaluated both by meniscus subluxation index (MSI) indicating the ratio of the extruded width of the medial meniscus to the width of medial meniscal body and by the medial radial displacement (MRD) indicating actual extruded width. The size of the osteophyte was assessed using a semi-quantitative whole-organ magnetic resonance imaging score (WORMS). The predictive accuracy of KOA was assessed by the area under the receiver operating characteristic curve (AUC) and optimal cutoff was determined for each parameter. ResultsThe AUC for MSI was 0.654 (0.561–0.748: 95% CI) and the cutoff value was determined as 17%. That for MRD was 0.677 (0.584–0.770) and the cutoff value was 2.2 mm. The AUC for the WORMS score at the posterior condylar notch was 0.667 (0.579–0.756) and the cutoff value was 2. ConclusionsSimilar predicting capacity of KOA development was found both in ME and osteophyte formation at the posterior condylar notch. Using these simple parameter, mas-screening for KOA development would be possible.

Radiographic Study of Humeral Stem in Shoulder Arthroplasty After Lesser Tuberosity Osteotomy or Subscapularis Tenotomy.

Lesser tuberosity osteotomy (LTO) and subscapularis tenotomy (ST) are used for takedown of the subscapularis during shoulder arthroplasty. LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis. However, humeral stem subsidence and loosening may be greater when osteotomy is performed, which may compromise functional outcomes. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique. Radiographs of 39 shoulders from 35 patients who underwent shoulder arthroplasty with a minimum of 1 year of radiographic follow-up were included in the study cohort. All patients received the same press-fit implant (Bigliani-Flatow; Zimmer Biomet). We collected data including demographic information; radiographic measurements, including humeral-acromial distance (HAD); subsidence; subluxation index; the presence of lucent lines >2 mm; and functional outcome scores using the Western Ontario Osteoarthritis of the Shoulder Index, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and the Constant score. Subsidence was 2.8 ± 3.1 mm for LTO vs 2.5 ± 3.1 mm for ST (P = .72). HAD did not differ between the LTO and ST groups preoperatively (9.5 ± 2.4 mm vs 10.9 ± 2.7 mm, P = .11). The first postoperative and final follow-up films for HAD for the LTO and ST groups showed a statistically significant difference (first postoperative film, 11.9 ± 3.7 mm vs 15.9 ± 4.5 mm, P = .005; final follow-up film, 11.8 ± 3.2 mm vs 14.5 ± 3.9 mm, P = .03). We identified no differences in subsidence, lucent lines >2 mm, posterior subluxation, and Constant, and DASH functional outcome scores for patients undergoing total shoulder arthroplasty via the LTO vs ST techniques with the same proximal collar press-fit humeral stem at short-term follow-up.

Femoral rotation and relationship between the femoral head and the acetabulum

Canine hip dysplasia is a debilitating hereditary orthopaedic disease with a high prevalence in dogs. The aim of this study was to describe the influence of internal or external rotation of the femur on the projected radiographic position of the patella within the trochlear groove, and on the femoral head in relationship to the acetabulum in the standard ventrodorsal hip extended view, i.e., medial or lateral patella displacement, Norberg angle, femoral head subluxation index and femoral head subluxation category. Eleven adult dog cadavers of large and giant breeds were radiographed in standard ventrodorsal hip extended view and with internal and external femoral rotation. The medial and lateral patella displacement, Norberg angle, subluxation index and subluxation category variables were measured on radiographs, and analysed comparing the normal position with positions of different degrees of internal or external rotation of the femur. In the normal ventrodorsal hip extended view, the patella was centred within the distal femoral metaphysis (P &amp;gt; 0.05). A mean ± SD internal femoral rotation of 16.0 ± 5.9° resulted in a medial patella index displacement of 0.23 ± 0.09, and a mean external femoral rotation of 17.9 ± 6.7° resulted in a lateral patella index displacement of 0.24 ± 0.1. The mean Norberg angle was 105.3 ± 4.3°, 107.7 ± 5.5° and 104.2 ± 4.3° (P &amp;lt; 0.05); the subluxation index was 0.15 ± 0.06, 0.12 ± 0.05 and 0.18 ± 0.06 (P &amp;lt; 0.05); the subluxation category was 1.55 ± 0.6, 1.46 ± 0.7 (P &amp;gt; 0.05) and 1.96 ± 0.65 (P &amp;lt; 0.05) in normal, internal and external femoral rotation ventrodorsal hip extended views, respectively. In conclusion, as the Norberg angle, subluxation index and subluxation category are parameters used for classification in the main international hip dysplasia scoring systems, adequate femoral position with the patella centred in the distal metaphysis is of uppermost importance to ensure the technical quality of radiographs.