Anterior Bone Loss Research Articles

Using Machine Learning Algorithms to Predict Postoperative Anterior Bone Loss Following Anterior Cervical Disc Replacement.

Machine learning model. This study aimed to develop and validate a machine learning (ML) model to predict moderate-severe anterior bone loss (ABL) following anterior cervical disc replacement (ACDR). A retrospective review of patients undergoing ACDR or Hybrid surgery (HS) at a single center was performed. Patients diagnosed as C3-7 single- or multi-level cervical disc degenerative diseases (CDDD) with more than 2years of follow-up and complete pre- and postoperative radiological imaging were included. An ML-based algorithm was developed to predict moderate-severe ABL based on perioperative demographic, clinical, and radiographic parameters. Model performance was evaluated in terms of discrimination and overall performance. A total of 339 ACDR segments were included (61.65% female, mean age 45.65 ± 8.03years). During a follow-up period of 45.65 ± 8.03months, 103 (30.38%) segments developed moderate-severe ABL. The model demonstrated good discrimination and overall performance according to precision (moderate-severe ABL: 0.71 ± 0.07, none-mild ABL: 0.73 ± 0.08), recall (moderate-severe ABL: 0.69 ± 0.08, none-mild ABL: 0.75 ± 0.07), F1-score (moderate-severe ABL: 0.70 ± 0.08, none-mild ABL: 0.74 ± 0.07), and area under the curve (AUC) (0.74 ± 0.10). The most important predictive features were higher height change, higher post-segmental angle, and longer operation time. Utilizing a ML approach, this study successfully identified risk factors and accurately predicted the development of moderate-severe ABL following ACDR, demonstrating robust discrimination and overall performance. By overcoming the limitations of traditional statistical methods, ML can enhance discovery, clinical decision-making, and intraoperative techniques.

More anterior bone loss in middle vertebra after contiguous two-segment cervical disc arthroplasty

BackgroundContiguous two-segment cervical disc arthroplasty (CDA) is safe and effective, while post-operative radiographic change is poorly understood. We aimed to clarify the morphological change of the three vertebral bodies operated on.MethodsPatients admitted between 2015 and 2020 underwent contiguous two-level Prestige LP CDA were included. The follow-up was divided into immediate post-operation (≤ 1 week), early (≤ 6 months), and last follow-up (≥ 12 months). Clinical outcomes were measured by Japanese Orthopedic Association (JOA) score, visual analogue score (VAS), and neck disability index (NDI). Radiographic parameters on lateral radiographs included sagittal area, anterior-posterior diameters (superior, inferior endplate length, and waist length), and anterior and posterior heights. Sagittal parameters included disc angle, Cobb angle, range of motion, T1 slope, and C2-C7 sagittal vertical axis. Heterotopic ossification (HO) and anterior bone loss (ABL) were recorded.Results78 patients were included. Clinical outcomes significantly improved. Of the three operation-related vertebrae, only middle vertebra decreased significantly in sagittal area at early follow-up. The four endplates that directly meet implants experienced significant early loss in length. Sagittal parameters were kept within an acceptable range. Both segments had a higher class of HO at last follow-up. More ABL happened to middle vertebra. The incidence and degree of ABL were higher for the endplates on middle vertebra only at early follow-up.ConclusionOur findings indicated that after contiguous two-segment CDA, middle vertebra had a distinguishing morphological changing pattern that could be due to ABL, which deserves careful consideration before and during surgery.

The association of cervical sagittal alignment with anterior bone loss following single-level anterior cervical surgery.

Anterior bone loss (ABL) is a common phenomenon after cervical disc replacement (CDR), which can also be observed after anterior cervical discectomy and fusion (ACDF). This study aimed to investigate the incidence and severity of ABL in single-level CDR and ACDF and explore the association of cervical sagittal alignment with ABL. This is a single-center retrospective cohort study. A total of 113 patients treated with CDR and 99 patients treated with ACDF were retrospectively reviewed from January 2014 to December 2018 in West China Hospital. Radiological data were collected at pre-operation, 1 week, 3 months postoperatively, and the last follow-up. The incidence and severity of ABL after both CDR and ACDF were evaluated. Cervical sagittal alignment parameters, including C0-C2 angle, cervical lordosis (CL), C2-C7 sagittal vertical axis (cSVA), T1 slope, functional spinal unit angle, disc angle, and surgical level slope, were evaluated. ABL was identified in 75 (66.4%) patients in the CDR group and 57 (57.6%) patients in the ACDF group. There were no significant differences in the incidence, severity, and location of ABL between the ACDF and CDR groups. For patients who underwent ACDF, the proportion of females was significantly higher in the ABL group (64.9% vs. 33.3%, P=0.002), whereas the body mass index (BMI) was significantly lower in the ABL group compared to the non-ABL group (22.72±3.09 vs. 24.60±3.04, P=0.002). No effect of ABL on the short-term clinical outcomes of ACDF and CDR was observed. In the ACDF group, patients with ABL had significantly smaller postoperative CL (11.83°±8.24° vs. 15.25°±8.32°, P=0.04) and cSVA (17.77±10.08 vs. 23.35±9.86 mm, P=0.007). In the CDR group, no significant differences were found in the cervical sagittal parameters between patients with and without ABL (CL: 12.58±8.70 vs. 15.46±8.50, P=0.10; cSVA: 20.95±8.54 vs. 19.40±9.43, P=0.38). ABL is common after both CDR and ACDF with comparable incidence and severity. Cervical sagittal alignment was closely related to ABL after ACDF yet had less influence on ABL after CDR.

Influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty in cervical spondylotic radiculopathy patients

To investigate the influence of preoperative symptom duration on effectiveness of cervical disc arthroplasty (CDA) in cervical spondylotic radiculopathy (CSR) patients. The clinical data of 90 CSR patients who underwent single-segment CDA between January 2008 and March 2020 and met the selection criteria were retrospectively analyzed. Based on preoperative symptom duration, patients were divided into an early intervention group (preoperative symptom duration <24 months) and a late intervention group (preoperative symptom duration ≥24 months). There was no significant difference in baseline data between the two groups ( P>0.05), including age, gender, body mass index, smoking status, surgical segment, preoperative neck disability index (NDI), visual analogue scale (VAS) score, cervical lordosis (CL), C 2-C 7 range of motion (ROM), disc angle (DA), disc ROM (DROM), and disc intervertebral height (DIH). The early intervention group had a slightly higher preoperative Japan Orthopedic Association (JOA) score than the late intervention group ( P<0.05). Perioperative indicators such as operation time, intraoperative blood loss, and postoperative hospital stay were recorded. The changes of JOA score, NDI, and VAS score at last follow-up compared with those before operation were used to evaluate the clinical efficacy, and the imaging evaluation of CL, C 2-C 7 ROM, DA, DROM, and DIH was performed before operation, immediately after operation, and at last follow-up. The incidence of prosthesis-related complications, including heterotopic ossification (HO), anterior bone loss (ABL), and prosthesis subsidence, was also assessed at last follow-up. Patients in both groups were followed up 24-120 months, with an average of 53.4 months. There was no significant difference in operation time, intraoperative blood loss, or follow-up duration between the groups ( P>0.05). However, the late intervention group had significantly longer postoperative hospital stay compared to the early intervention group ( P<0.05). At last follow-up, there was no significant difference in the changes of JOA score, NDI, and VAS score between the two groups before and after operation ( P>0.05). During the follow-up, there was no surgical revision in the two groups, and there was no significant difference in the incidence of HO, ABL, and prosthesis subsidence between the two groups at last follow-up ( P>0.05). Imaging evaluation showed that there was no significant difference in CL, C 2-C 7 ROM, DA, DROM, and DIH between the two groups at each time point before and after operation ( P>0.05). The intra-group comparison showed that the early intervention group could maintain the immediate postoperative CL at last follow-up, while the late intervention group had recovered to the preoperative level. Additionally, the C 2-C 7 ROM, DROM, and DA had all recovered to preoperative levels at last follow-up in both groups; meanwhile, the DIH significantly increased immediately after operation and sustained until the last follow-up. Preoperative symptom duration significantly affects the effectiveness of CDA in CSR patients. Patients with preoperative symptom duration ≥24 months have longer postoperative hospital stays and potentially poorer ability to maintain CL compared with patients with preoperative symptom duration <24 months.

Horizontal Ridge Augmentation in Class III Alveolus Defect According to the Elian and Tarnow Classification

Guided bone regeneration (ROG) is the process of reconstructing bone defects. The size of the alveolar ridge can be affected by loss of alveolar bone due to trauma or periodontal disease. In this case report, horizontal ridge augmentation with a xenograft and resorbable collagen membrane was used to restore anterior bone loss in a 69-year-old patient with stage IV generalized periodontitis, stage B periodontitis and stage III alveolar defects according to Elian and Tarnow. Treatment consisted of the extraction of the affected teeth. The results obtained over six months showed an increase in the horizontal ridge of 4.8 mm, demonstrating the efficacy of ROG in alveolar defects. Finally, the results of this case highlight the potential of ROG for horizontal flanges.

Changes in the centre of rotation and the anterior bone loss of the vertebral body in Mobi-C artificial disc replacement segments after cervical hybrid surgery: a retrospective study.

To examine the short-term efficacy and imaging results of using the Mobi-C in cervical hybrid surgery on 2-level cervical spondylolisthesis. To observe post-operative changes in the flexion-extension centre of rotation (FE-COR) and anterior bone loss (ABL) of the anterior cervical disc replacement (ACDR) segment. Forty-two patients (20 males and 22 females, aged 42‒67years) who underwent cervical hybrid surgery were retrospectively analysed. Their ACDR segment used Mobi-C, and the fusion segment used ROI-C, with a follow-up of 25‒42months (31.1 ± 4.8months). The modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and visual analogue scale (VAS) were used to assess clinical outcomes. Pre-operative, 6-month post-operative, and final follow-up radiographs were collected to compare total cervical spine curvature (C2-C7), curvature of the operated segments, range of motion (ROM) in the total cervical spine, operated segmental ROM, ACDR segmental ROM, and operated adjacent segmental ROM. The height of the superior articular process (HSAP), the orientation of zygapophyseal joint spaces (OZJS), and the length of the superior articular surface (LSAS) were measured. The FE-COR of the ACDR segment was measured using the mid-plumb line method. The translation distance of the Mobi-C was measured. The degree of disc degeneration in the adjacent segment, bony fusion of the ACDF segment, and ABL of the upper and lower vertebra of the ACDR segment were observed. In our group, all patients have shown improvements in their postoperative mJOA, NDI, and VAS scores. Overall cervical ROM and surgical segmental ROM decreased (P < 0.05). However, there was no significant decrease in ACDR segmental ROM and upper or lower adjacent segmental ROM compared with pre-operatively (P > 0.05). For FE-COR-X, only the last follow-up compared with pre-surgery showed statistical significance (46.74 ± 7.71% vs. 50.74 ± 6.92%, P < 0.05). For FE-COR-Y, the change was statistically significant at both 6months post-operation and the final follow-up compared to pre-operation (45.37% ± 21.11% vs. 33.82% ± 10.87%, 45. 37% ± 21.11% vs. 27.48% ± 13.58%, P < 0.05). No significant difference in the Mobi-C translation distance was observed (P > 0.05). Moreover, the difference in HSAP was not statistically significant at each node (P > 0.05). The OZJS and LSAS were significantly different at the final follow-up compared to the pre-operative period (P < 0.05). All the ACDF segments were observed in a stable condition at the final follow-up. Furthermore, 9 of the adjacent segments showed imaging ASD (9/82, 10.98%), and all were present at the last follow-up, of which 6 were mild, and 3 were moderate. Twenty of the 42 Mobi-C segments had no significant ABL (grade 0) 6months post-operatively (47.62%). Sixteen cases (38.10%) showed mild ABL (grade 1), and 6 cases (14.28%) showed moderate ABL (grade 2). No severe ABL occurred. The cervical hybrid surgery using Mobi-C artificial cervical discs can achieve satisfactory results. The Mobi-C segmental FE-COR-X shows a slow forward shift trend, and FE-COR-Y drops noticeably within 6months post-surgery before stabilizing. It's common to see mild to moderate ABL after cervical hybrid surgery using Mobi-C, and significant progression is unlikely in the short term. Furthermore, changes in the FE-COR after hybrid surgery in the Mobi-C segment might not affect clinical outcomes.

Cervical Disc Arthroplasty for the Treatment of Noncontiguous Cervical Degenerative Disc Disease: Results of Mid- to Long-Term Follow-up.

The long-term results of cervical disc arthroplasty (CDA) for noncontiguous cervical degenerative disc disease (CDDD) are still uncertain. Moreover, it is unclear whether CDA delays or avoids the degeneration of the intermediate segment (IS), leading to controversy in the field. Therefore, this study aimed to investigate the mid- to long-term clinical and radiographic outcomes of CDA in treating noncontiguous CDDD and to explore whether the IS degenerated faster after CDA than other non-surgically treated adjacent segments. We retrospectively analyzed patients with noncontiguous CDDD who underwent CDA in our department between January 2008 and July 2018. The patients were divided into the CDA and hybrid surgery (HS) groups, and clinical and radiographic outcomes were evaluated at routine postoperative intervals. Clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA), neck disability index (NDI), and visual analogue scale (VAS), while radiographic outcomes included cervical lordosis (CL), C2-C7 range of motion (ROM), segmental ROM, and disc angle (DA) at the arthroplasty level. Complications were also evaluated.Pre- and postoperative values were compared using paired t-tests or Wilcoxon rank-sum tests. Independent Student t-tests or Mann-Whitney U tests analyzed continuous data between CDA and HS groups, while chi-square or Fisher exact tests assessed categorical data. Sixty-four patients with noncontiguous CDDD, with 31 in the CDA group and 33 in the HS group, were evaluated. The mean follow-up time was over 70 months. The most frequently involved levels were C4/5 and C5/6. Both groups showed significant improvements in JOA, NDI, and VAS values after surgery. Although CL was maintained, the CL in the CDA group was consistently lower than that in the HS group (p < 0.05). There was a significant decrease in C2-C7 ROM (p < 0.05), but at the last follow-up, the C2-C7 ROM in the CDA group was greater than that in the HS group (p < 0.05). At the last follow-up, 44.3% of arthroplasty levels had developed heterotopic ossification (HO), and 48.45% had developed anterior bone loss (ABL). In addition, adjacent segment degeneration (ASDeg) was observed in the IS (22.7%), superior adjacent segment (20.6%)and inferior adjacent segment (21.9%). CDA or CDA combined with fusion are viable treatments for noncontiguous CDDD, with satisfactory outcomes after mid-to-long-term follow-up. ASDeg is similar in non-surgical segments after 70 months of follow-up. ROM of the IS issimilar to preoperative levels, indicating CDA does not increase the risk of IS degeneration.

Is Cervical Disc Arthroplasty an Effective Treatment for Cervical Degenerative Disease With Osteopenia?

Retrospective case-control study. To evaluate postoperative outcomes of single-level cervical disc arthroplasty (CDA) in patients with osteopenia and compare these results with a matched cohort of normal bone mineral density (BMD). Patients who had undergone single-level CDA were collected and screened. Included patients were divided into the osteopenia group and the normal group. 38 eligible patients with osteopenia were included in the final analysis. Subsequently, a 1:1 match was utilized. Clinical, radiographic data, and complications were recorded. Appropriate statistical methods were applied to conduct analysis using SPSS version 24.0. The mean follow-up time was 30.5 ± 27.3months. The osteopenia group achieved satisfactory clinical outcomes, with no significant intergroup differences. Additionally, there were no significant differences between groups in any of the radiological parameters, either in cervical alignment or segmental height, or range of motion. The radiological incidence rate of adjacent segmental degeneration and heterotopic ossification (HO) was comparable in both groups, respectively, with a similar composition of ROM-limiting HO. However, the osteopenia group had a tendency of more implant subsidence (2.7% vs 15.2%). The logistic regression analysis showed the osteopenia group had a significantly higher incidence rate of anterior bone loss (ABL) (OR = 5.37, 95% CI: 1.50 - 19.22). Single-level CDA for patients with osteopenia achieved similar satisfactory clinical outcomes compared with the normal BMD group. Meanwhile, the osteopenia group maintained adequate sagittal balance and segmental height. Based on this observation, this option may be feasible for selected patients with osteopenia.

Bone loss in shoulder instability: putting it all together.

Glenohumeral bone loss is frequently observed in cases of recurrent anterior and posterior shoulder instability and represents a risk factor for failure of nonoperative treatment. Patients with suspected glenoid or humeral bone loss in the setting of recurrent instability should be evaluated with a thorough history and physical examination, as well as advanced imaging including computed tomography (CT) and/or magnetic resonance imaging (MRI). In cases of both anterior and posterior instability, the magnitude and location of bone loss should be determined, as well as the relationship between the glenoid track (GT) and any humeral defects. While the degree and pattern of osseous deficiency help guide treatment, patient-specific risk factors for recurrent instability must also be considered when determining patient management. Treatment options for subcritical anterior bone loss include labral repair and capsular plication, while more severe deficiency should prompt consideration of bony augmentation including coracoid transfer or free bone block procedures. Concomitant humeral lesions are treated according to the degree of engagement with the glenoid rim and may be addressed with soft tissue remplissage or bony augmentation procedures. While critical and subcritical thresholds of glenoid bone loss guide the management of anterior instability, such thresholds are less defined in the setting of posterior instability. Furthermore, current treatment algorithms are limited by a lack of long-term comparative studies. Future high-quality studies as well as possible modifications in indications and surgical technique are required to elucidate the optimal treatment of anterior, posterior, and bipolar glenohumeral bone loss in the setting of recurrent shoulder instability.

Cervical collar use following anterior cervical hybrid surgery: protocol for a prospective randomized, time-controlled trial

IntroductionCervical hybrid surgery (HS) combines anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) to establish an individualized surgical plan for patients with multiple cervical disc degenerative diseases. In order to maintain the stability of the spine after HS, an external cervical collar is often used. However, there is still controversy regarding the importance of a cervical collar following surgery. This study aims to determine whether the cervical collar is effective and how long it should be worn after surgery.MethodsThis is a randomized, single-center, prospective, parallel-controlled trial. Eligible participants will be selected according to the inclusion and exclusion criteria. The primary outcome is the neck disability index, which will be evaluated before surgery and at one week, 3 weeks, 6 weeks, 3 months, 6 months, and 12 months following surgery. The secondary outcomes consist of the Japanese Orthopedic Association Scores, MOS 36-item short-form health survey (SF-36), visual analog scale, Pittsburgh Sleep Quality Index (PSQI), Bazaz dysphagia scoring system, Falls Efficacy Scale, cervical collar satisfaction score, neck soft tissue assessment, and Braden Scale, as well as radiologic assessments for cervical lordosis, disc height of the operative levels, fusion rate, range of motion (ROM), and complications including anterior bone loss, prosthesis migration, and heterotopic ossification. The clinical and radiologic examinations were performed by investigators with no therapeutic relationship with the individual patient. All radiographs were examined by one independent radiologist.Ethics and disseminationThe results of this study will be published in peer-reviewed journals and presented at conferences. Upon completion of this trial, our findings could provide an appropriate cervical collar-wearing guideline for patients receiving HS.Trial registrationChiCTR.org.cn ChiCTR2000033002. Registered on 2020–05-17.

Anterior bone loss: A common phenomenon which should be considered as bone remodeling process existed not only in patients underwent cervical disk replacement but also those with anterior cervical diskectomy and fusion.

Anterior bone loss (ABL) was considered as a non-progressive process secondary only to motion-preserving implant and has been noticed recently in cervical disk replacement (CDR) let alone patients with anterior cervical diskectomy and fusion (ACDF). Our purpose is to reveal this unnoticed phenomenon in ACDF and further explore its clinical and radiological outcomes. A total of 77 patients underwent ACDF with a minimum follow-up of at least one year were retrospectively reviewed. The average follow-up time was 22.51 ± 16.31months. There were 50 patients in group A with ABL, while there were 27 patients in group B without ABL. ABL was measured and classified into four grades according to Kieser's methods. Clinical evaluation, radiological parameters and fusion rate were recorded. The incidence of bone ABL was 64.9% of Zero-P and 55.2% of endplates. The incidence of upper and lower endplates was 61% and 49%, respectively, and such difference was not significant. Mild ABL occurred in 22%, moderate ABL in 38% and severe ABL of 40% patients underwent ACDF with ABL. ABL would not affect both clinical outcomes and fusion rate. However, ABL would result in a higher incidence of subsidence. ABL should be considered as a common phenomenon that both CDR and ACDF owned a non-progressive process which confined in one year. ABL would result in a higher incidence of subsidence. Luckily, this phenomenon does not have an effect on postoperative clinical and fusion rate.

Anterior Bone Loss after Cervical Baguera C Disc versus Bryan Disc Arthroplasty.

The objectives of this study were to identify the risk factors and incidence of anterior bone loss (ABL) after Baguera C cervical disc arthroplasty (CDA) and identify whether design differences in artificial discs affect ABL. In this retrospective radiological review of patients who underwent single-level Baguera C CDA in a medical center, the extent of ABL and the following radiological parameters were recorded: global and segmental alignment angle, lordotic angle (or functional spinal unit angle), shell angle, global range of motion (ROM), and ROM of the index level. ABL at the index level was grade 0-2. Grade 0 was defined as no remodeling, grade 1 as spur disappearance or mild change in body contour, and grade 2 as obvious bone regression with Baguera C Disc exposure. Combining grade 1 and grade 2, ABL was found in 56 upper adjacent vertebrae and 52 lower adjacent vertebrae of the 77 patients. Only 18 patients (23.4%) had no ABL. Shell angle differed significantly between ABL grades of both the upper and lower adjacent level: 0.0° in grade 0 and 1 ABL vs. 2.0° in grade 2 ABL of the upper adjacent level (p < 0.05); and 0.0° in grade 0 and 1 ABL vs. 3.5° in grade 2 ABL of the lower adjacent level (p < 0.05). A female predominance of ABL was found. Hybrid surgery and artificial disc size were also related to ABL. ABL is more common in Baguera C Disc arthroplasty than Bryan Disc arthroplasty. Larger shell angle was related to ABL after CDA with Baguera C Discs, which may indicate that shell angle is pivotal in determining the incidence of ABL after CDA. Females had more ABL with Baguera C Disc arthroplasty; this might be related to shorter endplate lengths as well as a smaller endplate-implant mismatch.

Arthroscopic-Assisted Anterior Glenoid Reconstruction Using Nonrigid Fixation With Distal Tibia Osteochondral Allograft

Introduction: Traumatic anterior glenohumeral instability events result in a capsulolabral (Bankart lesion) and/or osseous injury with subsequent attritional bone loss, particularly with recurrence. Up to 88% of patients with recurrent instability experience glenoid bone loss, which predisposes to future dislocations and subluxations, even with arthroscopic capsulolabral repair. The surgical management of glenoid bone loss includes a number of different techniques such as the Latarjet or coracoid transfer as well as other osseous and osteoarticular autografts and allografts. However, operative management of shoulder instability has increasingly shifted toward arthroscopic approaches with preservation of anatomy when possible. Indications: Arthroscopic-assisted allograft distal tibia bone block augmentation to the anterior glenoid is indicated for revision anterior glenohumeral instability procedures with anterior bone loss and in primary cases of anterior instability with critical bone loss. Technique: Our technique for nonrigid arthroscopic anterior glenoid reconstruction with allograft distal tibia and anterior labral repair is performed preferentially in the lateral position without necessitating patient repositioning. The preplanned tibial bone block is prepared on a back table prior to the arthroscopic procedure. After creation of portals and elevation of labral tissue, a guide and drill are used to introduce a retrograde reamer which is deployed to create a perpendicular edge for apposition of the allograft tibia. The bone block is then introduced through a rotator interval portal by pulling sutures retrograde through glenoid bone tunnels and is secured to the prepared surface medial to the liberated labrum. The articular surface of the graft and glenoid are aligned and suture-based fixation is used to compress the bone block against the native glenoid. The anterior labral tissue is then mobilized over the graft and repaired to the native glenoid when possible. Description/Conclusion: The benefits of allograft tibia augmentation for anterior instability with glenoid bone loss include an anatomic joint surface restoration including articular cartilage, lack of donor site morbidity, and a minimally invasive arthroscopic approach. When performed arthroscopically and with nonrigid fixation, this technique permits concurrent anterior labral repair and anatomic reconstruction, safe graft passage without necessity of a far medial portal, and expeditious return to function.

Early Experiences of One-Level Total Disc Replacement (Prestige LP) in Japan: A Comparison of Short-Term Outcomes with Anterior Cervical Discectomy with Fusion.

In Japan, cervical total disc replacement (TDR) was approved in 2017. However, because of its short history, no comparative study between cervical TDR and anterior cervical discectomy with fusion (ACDF) has been conducted in the country. Therefore, we examined and compared the surgical outcomes of TDR and ACDF for one-level cervical degenerative diseases. In total, 50 patients who had received anterior surgeries for one-level cervical degenerative diseases were investigated. Among them, 25 underwent TDR (Prestige LP; Medtronic), whereas the other 25 patients underwent ACDF. ACDF samples were selected from cases conducted before the approval of TDR (-2017.9) and were retrospectively judged to be indicated for TDR. Before and at 1 year after surgery, clinical and radiological outcomes were evaluated. No significant differences in terms of patient demographics between the two groups were observed. A longer operative time was observed in the TDR group than in the ACDF group. Postoperatively, no differences in the Japanese Orthopaedic Association score for cervical myelopathy (C-JOA) score, neck pain visual analog scale, C2-7 angle, and C2-7 range of motion (ROM) were determined. TDR tended to show better neck disability index (NDI) scores postoperatively when compared with ACDF. The local angle at operative level was larger in ACDF. In TDR, the local ROMs were maintained postoperatively; however, in ACDF, the local ROM at the operative level was decreased, and the local ROMs at adjacent levels were increased postoperatively. In the TDR group, although heterotopic ossification was observed in 11 patients (44.0%), and anterior bone loss was identified in 14 patients (56.0%), these issues did not affect surgical outcomes. Conclusively, no differences in terms of C-JOA score and neck pain between patients treated through TDR and ACDF were observed. However, a trend of better NDI scores was identified with TDR. While TDR maintained postoperative ROMs, ACDF showed an increase in the local ROMs at adjacent levels.

In Reply to the Letter to the Editor Regarding “Anterior Bone Loss in Cervical Disc Arthroplasty Correlates with Increased Cervical Lordosis”

In Reply to the Letter to the Editor Regarding “Anterior Bone Loss in Cervical Disc Arthroplasty Correlates with Increased Cervical Lordosis”

Letter to the Editor Regarding “Anterior Bone Loss in Cervical Disk Arthroplasty Correlates with Increased Cervical Lordosis”

Letter to the Editor Regarding “Anterior Bone Loss in Cervical Disk Arthroplasty Correlates with Increased Cervical Lordosis”

Anterior Bone Loss in Cervical Disc Arthroplasty Correlates with Increased Cervical Lordosis

Although cervical disc arthroplasty (CDA) has reportedly been associated with similarly low incidences of complications to anterior cervical discectomy and fusion, the phenomenon of anterior bone loss (ABL) is unique to CDA and has only recently gained notice. This study thus aimed to investigate the incidence of ABL and its correlation with cervical alignment post-operation. Consecutive patients who received CDA for herniated disc or spondylosis were retrospectively reviewed. The development and extent of ABL was detected by comparison of preoperative and postoperative serial images for the relative position of the anterior vertebral body with the CDA devices and graded into 3 levels: grade 1 (minor bone loss), grade 2 (anterior portion of the vertebral body without exposure of the artificial disc), and grade 3 (anterior portion of the vertebral body with exposure of the device). A total of 41 patients were analyzed with a mean follow-up of 24.1 months. Under serial radiologic examinations during follow-up, all patients (41 of 41= 100%) had bone loss of various degrees, with grade 3 ABL the most common (30 of 41= 73.1%). There were 8 and 3 patients who had grades 2 and 1 ABL, respectively. The changes of the Cobb angle (ΔCobb) trended towards higher grades of ABL. During the mean follow-up of 2 years, ABL was a common radiologic finding. More than half of the patients (26 of 41, 63.4%) in the series gained cervical lordosis (ΔCobb >0) after CDA. These patients with increased cervical lordosis (ΔCobb >0) after CDA had higher grades of ABL.

Anterior and posterior glenoid bone loss in patients receiving surgery for glenohumeral instability is not the same: a comparative 3-dimensional imaging analysis.

BackgroundAnterior and posterior glenoid bone loss morphology have both been individually and morphologically described in previous studies. While there exists substantial literature on anterior bone loss, and emerging evidence describing posterior bone loss, a direct comparison between the two is lacking in the current literature. The purpose of this study is to quantitatively compare the anatomic and morphological differences in glenoid bone loss (GBL) in operative patients with anterior versus posterior glenohumeral instability.MethodsAll patients over a 3-year period indicated for operative stabilization with posterior glenohumeral instability and suspected glenoid bone loss who underwent a computed tomography (CT) scan were reviewed. Included patients were then singularly matched by gender, laterality, and age (±3 years) to a collection of patients who presented for operative stabilization of anterior glenohumeral instability. GBL parameters were assessed based on the following characterizing measurements: (1) percentage of GBL, (2) glenoid vault version, (3) slope of the glenoid defect relative to the glenoid surface, (4) superior-inferior defect height, and (5) anterior-posterior defect width.ResultsSixty patients (30 anterior GBL, 30 posterior GBL) were included in the final analysis (60 males), with a mean age of 28.8 ± 8.15 years (range 16.0 to 51.0 years). Patients with anterior instability presented with higher GBL (24.94% ± 7.69 vs. 9.22% ± 5.58, P < .001), greater superior-inferior defect height (23.89 ± 4.21 mm vs. 21.88 ± 3.42 mm, P = .047), and steeper slope of glenoid defect (58.80° ± 11.86 vs. 38.59° ± 14.30, P < .001), while patients with posterior instability had greater retroversion (1.53° ± 4.04 vs. 7.59° ± 7.71, P < .001). Additionally, the anterior instability cohort had significantly more patients with moderate- to high-grade glenoid bone loss (n = 30) than patients with posterior instability (n = 11) (P < .001).ConclusionAnterior instability presents with a steeper slope of glenoid defect, higher percentage GBL, and greater superior-inferior defect height, whereas posterior instability presents with greater retroversion. This underscores the finding that anterior and posterior instability bone loss are not the same morphologically, and this should be considered in the operative treatment of glenohumeral instability.

It’s more than size that matters: The role of glenoid concavity in shoulder instability with anterior bone loss

It’s more than size that matters: The role of glenoid concavity in shoulder instability with anterior bone loss

Glenoid "Pear Restoration" with the Traditional Latarjet versus Congruent Arc Modification: CT Assessment of Coracoid Morphology for Preoperative Planning

Glenoid "Pear Restoration" with the Traditional Latarjet versus Congruent Arc Modification: CT Assessment of Coracoid Morphology for Preoperative Planning