Treatment Of Patellofemoral Instability Research Articles

Complications and Radiographic Outcomes of Tibial Tubercle Osteotomy at Minimum 5-Year Follow-up.

Tibial tubercle osteotomy (TTO) is a commonly utilized surgery in the treatment of patellofemoral instability and chondrosis. A number of case series studies have reported on the mid- and long-term outcomes with varying complication rates. To report the incidence of major complications after TTO and the rate of progression of knee osteoarthritis at midterm follow-up. Case series; Level of evidence, 4. All patients who underwent primary TTO between January 1, 2010 and December 31, 2015, and who had ≥5 years of clinical follow-up data were included. Patient demographics and clinical and radiographic outcomes were recorded. Risk factors for complications were identified using multivariate logistic regression analysis. A total of 72 patients were included. The mean follow-up period was 104.8 months (range, 67-138 months). The overall complication rate was 38.9% (28/72 patients), and the incidence of major complications was 6.9%. Univariate logistic regression analysis revealed that patients with a history of smoking were more likely to experience a complication (odds ratio = 4.33 [95% CI, 1.29-14.53]; P = .02). Multivariate analysis with TTO as the main predictor indicated that complication rates were not affected by TTO procedure (TTO vs TTO+other), number of screws, or distalization. There was also no difference between anteromedialization and medialization TTO techniques. The rate of patients with Kellgren-Lawrence grade 3 to 4 increased from 12.0% preoperatively to 23.9% at the final follow-up. New osteophyte formation was detected in 5.8% of patients on anteroposterior radiographs and in 9.1% of patients on lateral radiographs. In the current study, TTO was found to have a major complication rate of 6.9% at midterm follow-up. Smoking was a risk factor for major complications. Only 11.9% of patients had progression in tibiofemoral osteoarthritis at midterm follow-up.

Analyzing Alignment Error in Tibial Tuberosity–Trochlear Groove Distance in Clinical Scans Using 2D and 3D Methods

Background: Tibial tuberosity–trochlear groove distance (TT-TG) is often used as a primary metric for surgical decision-making in the treatment of patellofemoral instability (PFI), particularly when considering tibial tubercle transfer. Although TT-TG has high interrater reliability, it is prone to measurement differences caused by the alignment of the patient's leg in a scanner gantry, potentially influencing surgical decision-making. Quantification of this error within the clinical literature remains limited. Purpose: To quantify and specify the error in TT-TG caused by leg-scanner alignment by using detailed topographical landmarks and 3-dimensional (3D) analysis of computed tomography scans of patients with PFI. Study Design: Controlled laboratory study. Methods: Three-dimensional models of knees with PFI were created from computed tomography scans and used to identify TT-TG landmarks. TT-TG was measured using the established 2-dimensional (2D) and 3D methods. A model to estimate the differences between these 2 methods was created, and the orientation of the patients’ legs in relation to scanner longitudinal axis was measured to validate this model via linear regression. Interrater reliability was calculated via intraclass correlation coefficients (ICC). Results: A total of 44 knees of patients with PFI were analyzed. Differences between the 2D and 3D methods ranged from -4.0 to 14.7 mm (mean ± SD, 2.7 ± 4.1 mm) with a root mean square difference of 4.8 mm. The TT-TG distance of the 2D method (19.8 ± 7.2 mm) was significantly (P = .045) longer than that of the 3D method (17.1 ± 4.9 mm). The variance of the 2D method was significantly larger than that of the 3D method. In total, 13 (29.5%) of the knees had a difference of >5 mm between 2D and 3D TT-TG. The estimation model had an adjusted r2 value of 1.00 and a resulting root mean square difference of 0.21 mm. 3D TT-TGs interrater reliability was good to excellent (ICC, 0.94 [95 CI%, 0.81-0.98]). Conclusion: 3D TT-TG can be used to correct scanner-leg alignment errors, some of which are substantial when using only 2D TT-TG measurements. Clinical Relevance: The findings in this study suggest a need for caution and awareness of the potential effects of differences in alignment of the axes of the leg and scanner when using purely 2D TT-TG as a basis for surgical planning.

Trochleoplasty Provides Good Outcomes for Recurrent Patellofemoral Dislocations with No Clear Superiority across Different Techniques.

Background: Literature is sparse on outcome comparisons between different trochleoplasty techniques in the treatment of patella instability. To date, it is unclear whether there is a technique that offers superior outcomes. This systematic review and meta-analysis aims to compare and evaluate the outcomes of trochleoplasty techniques in the treatment of patellofemoral instability in trochlea dysplasia to establish whether there is an ideal choice of trochleoplasty technique for superior outcomes. Methods: 21 studies involving 880 knees were included. The mean age of the patients was 21.7 years (range 8-49 years). Mean follow-up timeframe of 43.5 months (range 8.8-100 months). Clinical outcomes assessed included rates of recurrence of patellofemoral dislocation, patient satisfaction, Kujala score, International Knee Documentation Committee (IKDC) score, Tegner score, and Lysholm score. Egger's test showed no publication bias across all outcomes assessed. Results: Favourable results were seen across all outcomes assessed and patient satisfaction. Improvements were seen with Kujala, IKDC, and Lysholm scores. Tegner scores showed good return to function. Post-operative dislocation and complication rates were low across the different techniques. Meta-regression for Kujala and IKDC scores showed good outcomes regardless of trochleoplasty technique used (Kujala, p = 0.549, relative risk 492.06; IKDC, p = 0.193, RR 0.001). The exact risk that trochleoplasty poses to the cartilage remains uncertain, as no study had a conservatively managed arm for comparison. Conclusions: Trochleoplasty yielded good outcomes irrespective of technique used with no clear superiority demonstrated in any technique in terms of outcome scores, satisfaction, post-operative dislocation rates or complications.

Patellofemoral Instability Part II: Surgical Treatment.

Treatment of patellofemoral instability in skeletally mature patients remains an important area of clinical and research interest. Both nonsurgical and surgical interventions are used to treat the underlying causes. Surgical management is the mainstay of treatment of recurrent PFI that fails nonsurgical treatment, and it is broadly classified into bony and soft-tissue procedures. Proximal bony procedures include femoral trochleoplasty, derotational osteotomies, and coronal alignment correction of the femur. Distal bony procedures include tibial tubercle transfer and derotational (supratubercle and infratubercle) osteotomies. Soft-tissue procedures consist of medial patellofemoral ligament repair or reconstruction and lateral lengthening procedures. This article is the second part of our two-article review on PFI, which focuses on surgical treatment options, their indications, outcomes, and potential complications.

Clinical Insights into the Treatment of Patellofemoral Instability with Medial Patellofemoral Ligament Reconstruction: Pearls and Pitfalls-Lessons Learned from 20 Years.

Patellofemoral instability is a prevalent cause of pain and disability in young individuals engaged in athletic activities. Adolescents face a particularly notable risk of patellar dislocation, which can be attributed to rapid skeletal growth, changes in q-angle, ligamentous laxity, higher activity levels, and increased exposure to risk. Specific sports activities carry an elevated risk of patellar dislocation. Younger age and trochlear dysplasia present the highest risk factors for recurrent patellar dislocations. International guidelines recommend conservative therapy following a single patellar dislocation without osteochondral lesions but suggest surgical intervention in recurrent cases. In this study, we have compiled current scientific data on therapy recommendations, focusing on MPFL (medial patellofemoral ligament) reconstruction. We discuss patient selection, surgical indications, graft selection, location and choice of fixation, graft tensioning, and postoperative care.

Sex-Specific Considerations and Evaluation of Trochlear Dysplasia in the Treatment of Patellofemoral Instability

Patella dislocation is a serious problem that disrupts athletic careers and influences quality of life, particularly when it is recurrent. The incidence of patellar dislocation has been shown to be most common in female adolescents. The causes of patellar dislocation are multifactorial, and the reasons for such sex-related differences are not well understood. A better understanding of risk factors such as trochlear dysplasia can help improve our treatment for this condition. While true for all athletes, attention to core stability, particularly with regard to lower limb mechanics, may be particularly important in female athletes with regard to reducing patella dislocation risk as well as ligament injury prevention, and should be explored further.

The role of trochleoplasty on treatment of patellofemoral instability

The role of trochleoplasty on treatment of patellofemoral instability

The Ali Krogius procedure for treatment of patellofemoral instability should be regarded as obsolete even in skeletally immature patients

BackgroundSeveral interventions are established for treating patellofemoral instability in adults. Fewer exist for pediatric patients without damaging the epiphysis. The Ali Krogius (AK) method is currently still being used. Most studies are not current and report varying results in small patient population. The aim of this study is to determine the long-term results of the AK method.MethodsIn this monocentric, retrospective study design, 33 knees in 33 patients who received the AK procedure for recurrent patellar dislocation were assessed. The average age was 20.8 years (range 6–40). The following functional scores were assessed: Kujala Score, Lysholm Score and Tegner Score. Subgroup analysis was done for patients ≤16 years of age. Available preoperative imaging was assessed for known risk factors.ResultsAfter an average follow-up of 7.8 years (Range 59–145 months), a total of 8 (24%) knees suffered a redislocation postoperatively. Seven of the eight dislocations occurred in patients ≤ 16 years of age. One knee (3%) was revised due to persistent pain. The median score was 86 points for the Kujala score and 90 for the Lysholm score. The median in the Tegner score was level 6. Clinically, the patellar glide was lateralized in 7 knees (21%) and an apprehension sign was triggered in 8 knees (24%).ConclusionsIncluding the present study, the existing literature indicates a redislocation rate between 24 and 41% following AK. It should thus be regarded as obsolete even though it protects the epiphysis. Surgical interventions such as medial patellofemoral ligament reconstruction with femoral drilling distal to the epiphysis should be preferred.Trial registrationRetrospectively registered: S-302/2016.Level of evidenceIII

An analysis of national variance in coding for patellofemoral instability

BackgroundWe sought to identify which specific set of codes are used by each acute NHS trust in England to document the diagnosis and management of patellofemoral instability (PFI). MethodsAll acute NHS Trusts in England were sent freedom of information (FOI) requests regarding their use of International Statistical Classification of Diseases and Related Health Problems version 10 (ICD-10) codes for the diagnoses related to PFI, and Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures 4th revision (OPCS-4) codes for surgical management of PFI. Results106 of 132 (80%) relevant trusts who manage patients with PFI responded with information. Coding for diagnosis of patellar dislocation and recurrent dislocation were largely consistent with 96% of the trusts using the same code. However, coding of patellar instability varied widely with 10 different codes being used, the most common of which was being used by only 34% of trusts. Coding for operative management exhibited greater variety with the number of different codes being used by trusts for each of the eight surgical treatments ranging from 11 to 19 and the range for the most common code being used by trusts from 34% to 64%. Furthermore, a large number of trusts used multiple different codes for the same diagnosis or treatment of PFI. ConclusionThere is a lack of uniformity in how trusts code PFI diagnosis and treatment. Standardisation will enable further research involving focused analysis of trust databases to facilitate a better understanding of the epidemiology of this condition.

Diagnostic Imaging of Patellofemoral Instability.

Throughout the literature, patellofemoral instability (PI) is defined as an increased risk of re-/luxation of the patella within the patellofemoral joint (PFJ). In most patients it is caused by traumatic patella luxation or the existence of a range of predisposing anatomic risk factors leading to an unphysiological movement sequence within the PFJ also known as patellofemoral maltracking. In order to provide an individualized therapy approach, clinical and radiological evaluation of those risk factors of variable magnitude becomes essential. Diagnostic imaging such as magnetic resonance imaging (MRI), plain radiography, and computed tomography (CT) are straightforward diagnostic tools in terms of evaluation and treatment of PI. In this review we performed a precise analysis of today's literature concerning the radiological evaluation of anatomic risk factors leading to PI. The purpose of the review is to present a logical compilation of the different anatomical risk factors causing PI and provide a straight overview of valuable radiological imaging techniques. PI is frequently based on a multifactorial disposition. The most relevant predisposing risk factors are trochlea dysplasia, rupture of the medial patellofemoral ligament (MPFL), patella alta, abnormal tibial tubercle to trochlea groove distance (TT-TG), femoral torsion deformities, and genu valgum. Although plain X-rays may provide basic diagnostic value, cross-sectional imaging (MRI, CT) is the standard radiological tool in terms of evaluation and detection of severity of predisposing anatomic variants leading to PI. · Based on today's literature, PI is characterized as an increased risk of patella re-/luxation within the PFJ.. · Underlying anatomic risk factors of variable magnitude mark the pathological cause of PI.. · Modern diagnostic imaging (MRI and CT) permits straightforward diagnosis of the typical features in terms of PI.. · To provide an individualized therapy approach, precise radiological evaluation and determination of the severity of predisposing anatomic anomalies are essential.. · Maas KJ, Warncke ML, Leiderer M et al. Diagnostic Imaging of Patellofemoral Instability. Fortschr Röntgenstr 2021; 193: 1019 - 1033.

Failure of Patellofemoral Joint Preservation

Abstract Patellofemoral instability is a common problem, but surgical management of patients with patellofemoral instability is complex. Surgical intervention is typically indicated for patients with recurrent dislocations, but surgery may be indicated even in first-time dislocators if there is a concomitant cartilage injury or if the patient has a poor prognosis based on evolving risk factors. Cartilage repair should be performed if possible, and additional procedures such as medial patellofemoral ligament (MPFL) reconstruction and/or tibial tubercle osteotomy (TTO) can be performed in conjunction with cartilage procedures. However, surgical decision-making and preoperative planning can be challenging. In this article, we outline the authors’ preferred techniques for performing these primary procedures in addition to recommendations to help avoid complications which can arise following MPFL reconstruction and TTO. The aims of this review are 1) to describe the indications and contraindications to the surgical procedures which can be utilized in the treatment of patellofemoral instability and associated cartilage injury, 2) to outline recommendations which can help when performing these procedures in the primary setting, and 3) to describe case examples which required revision procedures.

No growth disturbance after trochleoplasty for recurrent patellar dislocation in adolescents with open growth plates

Aims and Objectives:Trochlear dysplasia is the most important risk factor to patellofemoral instability in adolescents, therefore trochleoplasty to reshape the trochlear groove is the treatment of choice in patients with severe trochlear dysplasia. However, in the presence of open growth plates there is a potential risk of injury of the distal femoral growth plate and subsequent growth disturbance. Therefore, most authors do not recommend trochleoplasty in skeletally immature patients. The effect of trochleoplasty on femoral growth when performed before closure of the distal femoral physis remains unclear.The hypothesis of the study was, that In patients with open growth plates and an expected growth of less than two years trochleoplasty does not cause growth disturbance of the distal femur.Materials and Methods:18 consecutive adolescents (18 knees) with open physes and severe trochlear dysplasia underwent trochleoplasty. Pre- and postoperative radiographic examination included AP and lateral views to assess leg axis and patella alta. Preoperatively a radiograph of the left hand was performed to measure skeletal age. MRI was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TT-TG) distance. Evaluation included pre- and postoperative physical examination with evaluation of leg length and leg axis, Kujala score, Activity Rating Scale (ARS) and Tegner activity score.Results:The average age at the time of operation was 12.6 y (range, 12.2 - 13.3) in girls and 14.5 y (14.0 - 15.4) in boys. The average follow-up after operation was 2.3 years after surgery (range, 2.0 - 3.0 years). At follow-up in all patients the growth plates of the knee were closed. Impairment of growth of the distal femur was neither found clinically nor radiographically. No recurrent dislocation occurred. The median Kujala score and median VAS showed significant improvement (p < 0.01). The activity level according to the Tegner activity score did not change statistically significant.Conclusion:In this study, trochleoplasty as a treatment for patellofemoral instability in patients with open physes and an expected growth of not more than two years showed good clinical results without redislocation and no growth disturbance. Therefore, in selected adolescent patients with severe trochlear dysplasia trochleoplasty can be safely performed up to two years before the projected end of growth.

Medial Patellofemoral Ligament Reconstruction in Traumatic Patellar Dislocation without Patellar Fixation.

Acute traumatic patellar dislocation is a common injury, and spontaneous reduction may occur at the time of injury or may be reduced at the field of the accident by someone. It may be associated with osteochondral fractures and rupture of medial patellar stabilizers leading to recurrent patellar instability. The aim of this prospective study was to evaluate the outcomes of medial patellofemoral (PF) ligament (MPFL) reconstruction in recurrent traumatic patellar dislocation. Forty-five patients presented with PF instability as a result of traumatic rupture MPFL with normal patellar tracking underwent MPFL reconstruction without patellar fixation hardware through two parallel transpatellar tunnels and one screw in femoral tunnel. All patients were evaluated clinically preoperatively and at a minimum follow-up of 24 months, and International Knee Documentation Committee (IKDC) and Kujala scores were used to assess the clinical results. All patients were available for evaluation at a minimum of 24 months (up to 36 months). The mean age of these patients at the time of surgery was 22.82 years (range: 18-34 years). All patients gave history of trauma of their knees. Mean IKDC scale showed significant improvement as it rose from 47.17 preoperatively to 77.94 postoperatively, and mean Kujala score rose from 53.88 preoperatively to 86.24 postoperatively (p < 0.001). No recurrence of dislocation was recorded. Only three patients had mild atrophy of thigh and one patient had some difficulty in jumping. Reconstruction of MPFL by this method provides good clinical result in the treatment of PF instability by using autologous graft (semitendinosus and gracilis). Less hardware were used with less complications.

CURRENT PRACTICE TRENDS IN THE SURGICAL MANAGEMENT OF PATELLOFEMORAL INSTABILITY; A SURVEY OF THE PEDIATRIC RESEARCH IN SPORTS MEDICINE (PRiSM) SOCIETY

Background: Patellofemoral instability in young athletes presents both diagnostic and management dilemmas for which consensus often does not exist. Surgical options and treatments are heterogeneous among orthopaedic surgeons. The purpose of this study is to survey members of the Pediatric Research in Sports Medicine (PRiSM) Society regarding their practice and treatment for patellofemoral instability and to identify trends in management of patellofemoral instability in children and adolescents nationwide. Methods: A 27-question multiple choice online survey was distributed to the members of the PRiSM Society. The survey was sent via email 3 times over a six week time span after which time the survey was closed. Members were asked about clinical and imaging evaluation, methods of conservative treatment, surgical indications, and surgical techniques when treating patellofemoral instability. Results: 65/70 (93%) of respondents reported performing surgery for patella instability more than 5 times in the past year. Of these 65, 56 respondents completed the questionnaire in its entirety. While some trends regarding treatment emerged, the respondent data demonstrated the large discrepancies in practice patterns that exist nationwide. 48% (27/56) of respondents obtained an MRI for patients with a 1+ knee effusion or greater on exam within one week after a first-time traumatic patellar dislocation while 20% (11/56) obtain an MRI in all patients presenting with a patella dislocation. To assess skeletal maturity, 75% (42/56) of respondents obtained knee x-rays to evaluate the physes around the knee, whereas 53% (30/56) obtained a hand x-ray to assess bone age. 41% (23/56) of respondents reported that surgical intervention for fragment refixation or loose body removal is indicated anytime there is evidence of a loose body or osteochondral fragment regardless of fragment size. 11% (6/56) reported only performing osteochondral fracture repair when the fragment was large enough to repair. If surgery is performed for an osteochondral loose body, 38% (21/56) of respondents performed an MPFL reconstruction. 59% (33/56) reported performing the MPFL reconstruction in children and adolescent athletes with hamstring allograft, while 30% (17/56) prefer autograft (hamstring, quadriceps). MRI was strongly preferred over CT when considering a tibial tubercle anteromedialization. TT-TG distance is the diagnostic measurement of choice with no respondents selecting TT-PCL as their preferred diagnostic measurement. The indication for surgical correction of angular deformity in the setting of patellar instability had mixed responses. 18% (10/56) would indicate surgery when the mechanical axis is lateral to the center of the lateral femoral condyle, while others considered this angular correction only when the patient is skeletally immature or when the mechanical axis is lateral to the lateral tibial spine. For surgical recommendations in a patient with significant trochlear dysplasia, 46% (26/56) reported no surgical management of trochlear dysplasia in first-time surgery while 41% (23/56) reported no surgical management of trochlear dysplasia in first-time or revision surgery. Conclusion: There was significant heterogeneity among respondents that highlights a lack of consensus regarding optimal diagnostic and treatment algorithms. Understanding management trends nationwide may help practicing surgeons gain insights and develop evidence based treatment algorithms to best serve patients with this condition.

Current Concepts in the Treatment of Patellofemoral Instability

Background and Hypothesis: &#x0D; Patellofemoral instability represents a disabling condition, which presents primarily in active, young patients with an increased incidence in the female sex. A patellar dislocation can occur from a high-energy trauma or from an atypical anatomy, such as trochlear dysplasia, patellar dysplasia, patella alta, increased tibial tuberosity-trochlear groove (TT-TG) distance, increased Q-angle, and ligamentous laxity. When a patient presents with patellofemoral instability, the orthopedic surgeon faces many decisions regarding the treatment. Since the risk of a second dislocation after an acute dislocation resides at approximately 17%, many orthopedic surgeons treat the first patellar dislocation non-operatively barring the patient lacks any atypical anatomy. However, after a second dislocation, the likelihood of recurrent dislocations increases to approximately 50%, which directs most orthopedic surgeons to surgical treatment. The current work reviews the anatomical predispositions, clinical presentation, and treatment of patellofemoral instability. &#x0D; Experimental Design or Project Methods: &#x0D; The review was constructed via an extensive literature search utilizing the databases of MEDLINE/PubMed, SportDiscus, CINAHL, and Cochrane Central Register of Controlled Trials. &#x0D; Results: &#x0D; Multiple treatments exist for patellofemoral instability, which include non-operative treatment, MPFL reconstruction, tibial tubercle osteotomy, and trochleoplasty, along with many other procedures. Each case requires a tailored approach to successfully treat the patellofemoral instability. &#x0D; Conclusion and Potential Impact: &#x0D; Patellofemoral instability represents a potentially debilitating condition of anterior knee pain and limited activity. Understanding the anatomical predispositions, clinical presentation, and treatment of patellofemoral instability marks the first step to caring for patients with this condition.

Clinical Results after Combined Distal Femoral Osteotomy in Patients with Patellar Maltracking and Recurrent Dislocations.

The purpose of this study is to analyze the clinical results after treatment of patellofemoral instability and maltracking caused by torsional or axial deformities of the lower extremity by combined distal femoral osteotomies (DFOs). We analyzed 31 DFOs (25 patients) with patellar maltracking and instability, treated in our clinic. Torsional angles and the leg axis in the frontal plane were measured preoperatively. Standardized scoring systems were determined pre- and postoperatively including a clinical examination. Nineteen cases of torsional and 12 cases of axis deformities were evaluated 27 (12-64) months postoperatively. Among those with torsional deformity, mean femoral torsion was -39.0 ± 8.8 degrees, tibial tuberosity to trochlear groove (TT-TG) 20.3 ± 4.5 mm. We performed 19 torsional (+11.4 ± 2.4 degrees) DFOs with medial patellofemoral ligament (MPFL) augmentation (n = 19), tibial tuberosity transfer (n = 14, 10.9 ± 6.0 mm), varus (n = 4, 3.3 ± 1.0 degrees), or valgus (n = 1, 7.0 degrees) correction. Among valgus deformities, the leg axis was 6.7 ± 2.3 degrees valgus and TT-TG 19.3 ± 5.0 mm. We performed 12 medially closing-wedge DFOs (7.6 ± 2.8 degrees) with MPFL augmentation (n = 12) and tibial tubercle transfer (n = 9, 11.4 ± 7.3 mm). Visual analogue pain scale improved from 6.2 to 1.5 (p = 0.000), Kujala score from 45.0 to 81.5 (p = 0.000), Lysholm score from 40.3 to 83.9 (p = 0.000), and Tegner score from 2.1 to 3.9 (p = 0.000). Preoperative cartilage damage significantly influences the postoperative functional outcome (Lysholm score) (p = 0.026) as well as the improvement in terms of the Kujala score (p = 0.045) in the overall collective. No redislocation was observed. Patellofemoral maltracking and instability in torsional and axis deformities can successfully be treated by combined DFOs with excellent clinical results. The coexistence of risk factors for patellar instability requires a combination of additional procedures to complement the osteotomy. Preoperative cartilage lesions significantly influence the clinical outcome.

Highly variable tibial tubercle-trochlear groove distance (TT-TG) in osteoarthritic knees should be considered when performing TKA.

The tibial tubercle-trochlear groove distance (TT-TG) is an established measurement to assist diagnosis and treatment of patellofemoral instability. However, little is known about the distribution of TT-TG in osteoarthritic knees. The purpose of the current study is to investigate the TT-TG in a large cohort of osteoarthritic knees and to analyse, in particular, the association of knee alignment and TT-TG. Data from 962 consecutive patients [455 male, 507 female; mean age±SD 70.8±9.3 (37-96)] who had undergone 3D-CT and preoperative knee planning with validated commercial 3D planning software before total knee arthroplasty (TKA) were collected prospectively. The TT-TG, coronal hip knee ankle angle (HKA), femoral anteversion (AVF), external tibial torsion (ETT), and femorotibial rotation (Rot FT) were analysed. Pearson correlations were performed to assess correlations between TT-TG, mechanical axis, and rotational parameters (p < 0.05). HKA showed a strong correlation with TT-TG (r = 0.488; p < 0.001) with 98 (67.1%) and 45 (30.8%) of valgus knees having respective abnormal and pathological TT-TG values. There were no significant correlations between parameters of rotational alignment (AVF, ETT, Rot FT) and TT-TG. Mean TT-TG was 12.9±5.6mm, ranging from 0.0 to 33.7mm. 325 (33.8%) of all patients had abnormal (> 15mm) and 101 (10.5%) had pathological (> 20mm) values. A varus alignment was present in 716 (74.4%) of the cases (HKA <- 1.5°), a neutral alignment in 100 (10.4%), and a valgus alignment in 146 (15.2%) (HKA > 1.5°). A wide variation of TT-TG values in osteoarthritic knees was shown by our results. There was a relevant influence of coronal limb alignment on the TT-TG-the more valgus the higher and more pathological the TT-TG. With the aim of having a more personalised TKA, the individual TT-TG should be taken into account to improve the outcome. III. Retrospective cohort study.

Treatment of patellofemoral instability in adolescent by anatomical double-bundle medial patellofemoral ligament reconstruction with double suture anchor technique

To explore the clinical outcomes of anatomical double-bundle medial patellofemoral ligament (MPFL) reconstruction with double suture anchor technique in treating patellofemoral instability in adolescent. Methods: Twenty-five young people with patellofemoral instability (25 knees) in our department from January 2013 to December 2014 were enrolled for this study. All patients were performed anatomical double-bundle MPFL reconstruction with arthroscopic-assisted suture anchors technique in the patella, and fixed in the femoral socket with absorbable interference screw. All patients are evaluated by different methods, including patient's satisfaction, patellar apprehension test, recurrent subluxation/dislocation, CT assessment of bone tunnel and patellar tilt angle. Lysholm scores, Tegner scores and Kujala scores were recorded at the final follow-up. Results: The mean follow-up was 24 (range 20-40) months. All cases were observed in negative patellar apprehension test. Infection, recurrent subluxation/dislocation and patellar fracture were not found at the last follow-up. CT results demonstrated that the tunnel position were good. The patellar tilt angle was decreased from 21.6°±2.3° to 10.5°±1.6° (P<0.05); the Lysholm scores was increased from 51.7±5.3 to 93.8±6.5 (P<0.05). Tegner scores was increased from 4.1±1.1 to 5.5±0.6 (P<0.05). Kujala scores was increased from 53.5±6.4 to 94.6±4.3 (P<0.05). Conclusion: Arthroscopic-assisted anatomical double-bundle MPFL reconstruction with the suture anchors technique is a safe, minimal invasive and effective surgical option for treating patellofemoral instability in adolescent.

Patellofemoral instability in skeletally immature patients

BackgroundPatellofemoral instability is a common cause of knee disability. Acute patellofemoral dislocation is the most common acute knee disorder in skeletally immature patients. In this group, the incidence of patellofemoral dislocation is approximately 43 per 100,000 individuals. The precise objective addressed in the paperMedial patellofemoral ligament (MPFL) reconstruction has a significant role in the treatment of patellofemoral instability in skeletally immature patients. We evaluated the medium and long-term results results of MPFL reconstruction as the sole method of patellofemoral instability treatment and their relationship with the presence of other potentially associated factors. MethodsWe conducted a prospective study with 35 young patients who underwent the same surgical technique between 2002 and 2009. Age, gender, patellar tilt, patella height, TT-TG, trochlear dysplasia, the Kujala score and the Tegner activity score were evaluated. Statistical analysis used SPSS® 20. ResultsThe mean age of the patients was 15.9 years. High patella was observed in 10% of patients. All patients had TT-TG within a normal range. Trochlear dysplasia was found in 80% of the patients: 40% had Dejour's type A; 34% type B; 20% type C and 6% type D. The medium-term Kujala score (84±9) significantly improved compared to the pre-operative score (54±11). However, a decline in the long-term (78±3) score was observed. The Tegner activity score showed a significant decrease. The long-term results were significantly lower when patients had trochlear dysplasia type B to D. ConclusionsA decade after isolated MPFL reconstruction, results remained satisfactory. Patients with trochlear dysplasia types B to D may benefit from associated trochleoplasty in a second intervention.

Operative Management of Patellar Instability in the United States: An Evaluation of National Practice Patterns, Surgical Trends, and Complications.

Background:Treatment of patellofemoral instability has evolved as our understanding of the relevant pathoanatomy has improved. In light of these developments, current practice patterns and management trends have likely changed to reflect these advancements; however, this has not been evaluated in a formal study.Purpose:To determine nationwide patient demographics, surgical trends, and postoperative complications associated with the operative management of patellar instability surgery.Study Design:Descriptive epidemiological study.Methods:A large private-payer database (PearlDiver) comprising patients covered by Humana and United Healthcare insurance policies was retrospectively reviewed using Current Procedural Terminology (CPT) codes to identify patients who underwent surgery for patellar instability. The study cohort was established by querying for patients billed under CPT codes 27420, 27422, or 27427 while satisfying the diagnostic requirement of patellar instability (International Classification of Diseases–9th Revision codes 718.36, 718.86, or 836.3). Patient demographics, surgical trends, concomitant procedures, and postoperative complications were determined.Results:A total of 6190 patients underwent surgical management for patellar instability. Adolescents (age range, 10-19 years) represented 51.5% of cases, and 59.6% were female. The number of patellar instability procedures increased annually over the study period in both the Humana (P = .004, R 2 = 0.76) and United Healthcare (P = .097, R 2 = 0.54) cohorts. The most common concomitant procedures were lateral retinacular release (43.7%), chondroplasty (31.1%), tibial tubercle osteotomy (13.1%), removal of loose bodies (10.5%), osteochondral grafting (9.5%), and microfracture surgery (9.5%). Manipulation under anesthesia was required in 4.6% of patients within 1 year. Patellar fracture within 1 year and infection within 30 days occurred in 2.1% and 1.2% of patients, respectively.Conclusion:Patellar instability surgery has increased over the past decade. This finding may be attributed to growing clinical evidence to support these procedures as well as increased surgeon familiarity and comfort with these specific techniques. We observed an unexpectedly high rate of concomitant lateral retinacular release. Overall, the rates of commonly recognized complications (stiffness, patellar fracture, and postoperative infection) were similar to those observed in smaller case series.