Release of the medial collateral ligament is mandatory in medial open-wedge high tibial osteotomy.

PURPOSE: The purpose of this study was to quantify the effect of clinically relevant open-wedge high tibial osteotomies on medial collateral ligament (MCL) strain and the resultant tibiofemoral contact mechanics during knee extension and 30° knee flexion. METHODS: Six human cadaveric knee joints were axially loaded (1 kN) in knee extension and 30° knee flexion. Strains at the anterior and posterior regions of the MCL were determined using strain gauges. Tibiofemoral contact mechanics (contact area, mean and maximum contact pressure) were investigated using pressure-sensitive sensors. Open-wedge osteotomy was performed using biplanar cuts and osteotomy angles of 5° and 10° were maintained using an external fixator. Tests were performed first with intact and then with dissected MCL. RESULTS: Nonparametric statistical analyses indicated a significant strain increase (p < 0.01) in the anterior and posterior fibres of the MCL with increasing osteotomy angle of up to 8.3% and 6.0%, respectively. Only after releasing the MCL the desired lateralisation of the mechanical axis was achieved, indicating a significant decrease in the maximum contact pressure in knee extension of - 25% (p = 0.028) and 30° knee flexion of - 21% (p = 0.027). CONCLUSIONS: The results of the present biomechanical study suggest, that an open-wedge high tibial osteotomy is most effective in reducing the medial contact pressure when spreading the osteotomy to 10° and concomitantly releasing the MCL. To transfer the results of this biomechanical study to the clinical day-to-day practice, it is necessary to factor in the individual ligamentous laxity of each patient into the treatment options e.g. particularly for patients with distinct knee ligament laxity or medial ligamentary instability, the release of the MCL should be performed with care. LEVEL OF EVIDENCE: Controlled laboratory study.

Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft shows favourable results at a minimum of 2-year follow-up.

PURPOSE: In adults, reconstruction of the medial patellofemoral ligament (MPFL) has shown good results. Treatment for recurrent patellar instability in children and adolescents with open growth plates, however, requires alternative MPFL reconstruction techniques. This study presents the outcomes of a minimally invasive technique for anatomic reconstruction of the MPFL in children using a pedicled superficial quadriceps tendon graft, hardware-free patellar graft attachment, and anatomic femoral fixation that spares the distal femoral physis. METHODS: Twenty-five consecutive patients with patellofemoral instability and open growth plates underwent anatomic reconstruction of the MPFL using a pedicled superficial quadriceps tendon graft. Preoperative radiographic examination included AP and lateral views to assess patella alta and limb alignment. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove distance. Evaluation included pre- and post-operative physical examination, Kujala score, visual analog scale (VAS), and Tegner activity score. RESULTS: The average age at the time of operation was 12.8 years (9.5-14.7). The average follow-up after operation was 2.6 years (2.0-3.4). No recurrent dislocation occurred. Twenty patients were very satisfied (80%), four patients were satisfied (16%), and one patient was partially satisfied with the surgical procedure (4%). No patient was dissatisfied. The median Kujala score significantly improved from 63 (44-81) preoperatively to 89 (77-100) post-operatively (P < 0.01), and the median VAS score improved significantly from 4 (1-7) to 1 (0-4) (P < 0.01). The Tegner activity score increased, but not significantly, from 4 (3-8) preoperatively to 5 (3-8) post-operatively (non-significant). CONCLUSION: The described technique for MPFL reconstruction with a pedicled quadriceps tendon is a safe and effective technique with good clinical results and allows patients to return to sports without redislocation of the patella. It might therefore be a valuable alternative to more extensive procedures in paediatric and adolescent patients. LEVEL OF EVIDENCE: Prospective study, Level III.

Results of medial patellofemoral ligament reconstruction compared with trochleoplasty plus individual extensor apparatus balancing in patellar instability caused by severe trochlear dysplasia: a systematic review and meta-analysis.

PURPOSE: Many studies have reported satisfactory clinical outcomes and low redislocation rates after reconstruction of the medial patellofemoral ligament (MPFL) for the treatment of lateral patellar instability. Despite uncorrected severe trochlear dysplasia (Dejour type B to D) being acknowledged as a major reason for less favourable clinical outcomes and a higher incidence of patellar redislocations after an isolated MPFL reconstruction, the evidence for a deepening trochleoplasty procedure remains scarce in the current literature. The hypothesis of this systematic review and meta-analysis was that a deepening trochleoplasty in combination with an a la carte extensor apparatus balancing procedure provides lower redislocation rates and superior clinical outcomes than isolated MPFL reconstruction in patients with lateral patellar instability caused by severe trochlear dysplasia. METHODS: A systematic review of the literature was conducted using specific inclusion and exclusion criteria for clinical studies reporting index operations (trochleoplasty and MPFL reconstruction) for the treatment of patellar instability caused by severe trochlear dysplasia. The Kujala score was analysed as the primary clinical outcome parameter in a random effects meta-analysis. RESULTS: Ten uncontrolled studies with a total of 407 knees (374 patients) were included in this analysis. The MPFL group comprised 4 studies with a total of 221 knees (210 patients), and the trochleoplasty group comprised 6 studies with a total of 186 knees (164 patients). The mean preoperative Kujala score ranged between 50.4 and 70.5 in the MPFL group and between 44.8 and 75.1 in the trochleoplasty group. The pooled Kujala score increased significantly by 26.4 (95% CI 21.4, 31.3; P < 0.00001) points in the MPFL group and by 26.2 (95% CI 19.8, 32.7; P < 0.00001) points in the trochleoplasty group. The post-operative patellar redislocation/subluxation rate was 7% in the MPFL group and 2.1% in the trochleoplasty group. CONCLUSION: This analysis found significant post-operative improvements in patient-reported outcomes for patients undergoing both an MPFL reconstruction and in those undergoing a trochleoplasty plus an individual extensor apparatus balancing procedure when assessed using the Kujala score. The likelihood of preventing the patella from subsequent post-operative redislocation/subluxation was, however, greater in patients who underwent trochleoplasty plus extensor balancing. LEVEL OF EVIDENCE: IV.

Combined supracondylar femoral derotation osteotomy and patellofemoral ligament reconstruction for recurrent patellar dislocation and severe femoral anteversion syndrome: surgical technique and clinical outcome.

PURPOSE: Severly increased femoral anteversion is an important risk factor for patellofemoral instability. Recurrent dislocations cause a traumatic disruption of the medial patellofemoral ligament. Therefore a procedure that combines femoral derotation osteotomy and patellofemoral ligament reconstruction should be considered for patients with severely increased femoral anteversion. The aim of the study was to evaluate the subjective and objective outcomes after combined femoral derotation osteotomy and anatomical reconstruction of the MPFL. METHODS: 12 consecutive patients (12 knees) with patellofemoral instability and severely increased femoral anteversion underwent combined femoral derotation osteotomy and anatomical reconstruction of the MPFL. Preoperative radiographic examination included AP and lateral views to assess patella alta. MRI was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TT-TG) distance. Additionally, MRI assessment of the rotational profile was performed. Evaluation included evaluation of cartilage injuries, preoperative and postoperative physical examination, visual analog scale (VAS), Kujala score, International Knee Documentation Committee score (IKDC), Activity Rating Scale (ARS) and Tegner activity score. RESULTS: The average age at the time of operation was 18.2 years (range, 15-26 years). The average follow-up after operation was 16.4 months postoperatively (range, 12-28 months). No recurrent dislocation occurred. The results showed a significant improvement of the Kujala score, IKDC score and VAS (p < 0.01). The activity level according to the Tegner activity score and ARS did not show statistically significant changes (p = 0.75; p = 1.0). CONCLUSION: Combined anatomical reconstruction of the MPFL and femoral derotation osteotomy resulted in significant improvement of knee function and good patient satisfaction in young patients with severely increased femoral anteversion. No re-dislocation of the patella occured.

Return to work and sporting activities after high tibial osteotomy.

PURPOSE: High tibial osteotomy (HTO) is a commonly used treatment to correct varus malalignment of the knee. The purpose of this study was, first, to determine, whether HTO allows return to pre-operative work, depending on the amount of work load. Second, the restoration of sports ability and a difference in sports activities pre- to postoperative should be analyzed. METHODS AND PATIENTS: Fifty-one patients were included in this study. Patients were divided into three groups dependent on work intensity. Sporting activity was evaluated by an activity score (Naal). Clinical examination includes Tegner-score, Lysholm-score and visual analog pain scale. General health was assessed using the 36-Item Short Form Survey questionnaire. RESULTS: On an average of 16.7 ± 15.6 weeks after surgery patients returned to work, and 93.8 % of the patients returned to pre-operative work load. The Tegner activity score did not show significant changes pre- and postoperatively. At the time of survey Lysholm score reached a value of 68.7 ± 23.9 points on average. Postoperatively, patients remarked on decreased pain by VAS by an average of 2.6 ± 2.3 points. CONCLUSIONS: In total, 92.3 % returned to pre-operative sports activities after surgery. A shift away from high impact activities to lower impact activities, a significant decrease of the duration of sports activities and number of sports disciplines was detected. In summary, HTO allows the young, active patient with medial osteoarthritis of the knee to return to work with the same work intensity and to return to sports.

Analysis of failure and clinical outcome after unsuccessful medial patellofemoral ligament reconstruction in young patients.

PURPOSE: Reconstruction of the medial patellofemoral ligament (MPFL) has become a popular procedure for patients with patellofemoral instability. Nevertheless, complication rates of up to 26 % have been reported. This study presents the analysis of failure and clinical outcome of subsequent revision surgery in young patients following unsuccessful medial patellofemoral ligament reconstruction. METHODS: Nineteen consecutive patients with unsuccessful MPFL reconstruction underwent revision surgery. Pre-operative assessment included physical examination, radiographs and magnetic resonance imaging to assess the MPFL graft, trochlear dysplasia, tibial tubercle-trochlear groove (TT-TG) distance, patella alta and femoral tunnel positioning. Evaluation also included the detection of cartilage injuries as well as visual analog scale (VAS), knee function scores and patient satisfaction. Each complication was analysed and an appropriate revision procedure was performed according to the identified technical or untreated anatomical risk factor. RESULTS: The average age at the time of the index operation was 20.2 years (range, 16-27 years). The average age at the time of the primary MPFL reconstruction was 18.4 years (range, 15-25). Three main reasons for failure after MPFL reconstruction could be identified: failure to consider additional risk factors, intra-operative technical errors and inappropriate patient selection. In five patients severe trochlear dysplasia and in two patients concomitant excessive femoral anteversion as additional risk factors were detected. Seven patients experienced medial retinacular pain with limited flexion due to technical errors caused in three patients by anterior placement of the femoral tunnel and in four others by overtensioning of the MPFL graft. Four patients with patellofemoral pain were found to have ICRS grade III or IV cartilage injuries. The median postoperative Kujala scores improved from 57 (34 - 73) pre-operatively to 83 (49 - 94), the median knee function improved from 5 (range, 2 - 6) pre-operatively to 8 (range, 3 - 10). Median VAS scores improved from 4 (2 - 7) to 2 (0 - 5). A total of 78.9% of patients were satisfied or very satisfied, 15.8% were partially satisfied and one patient (5.3%) was not satisfied with the result after revision surgery. CONCLUSION: Failure to consider additional risk factors, technical intra-operative errors and inappropriate patient selection were identified as reasons for revision surgery after MPFL reconstruction. Identifying the potential causes of failure can help to treat and possibly prevent future complications.

Clinical outcome and magnetic resonance imaging after osteochondral autologous transplantation in osteochondritis dissecans of the talus.

BACKGROUND: Osteochondral autologous transplantation (OAT) has been performed for years for osteochondritis dissecans of the knee with good clinical results. In osteochondritis dissecans of the talus, however, OAT represents a challenge to the orthopaedic surgeon as frequently malleolar osteotomy has to be performed for exposure of the talus and the harvesting of the osteochondral graft usually requires an arthrotomy of the knee. METHODS: In this study, we evaluated the clinical outcome of OAT in 32 patients (mean follow-up 29 months) by means of the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, ankle pain on the visual analogue scale (VAS), HSS Patella Score, and magnetic resonance imaging (MRI) of the osteochondral graft. RESULTS: Median AOFAS score was 86, median ankle pain on VAS was 2.0, and median HSS Patella score was 95. Complications included 1 case of delayed wound healing and 1 case of nonunion of the malleolar osteotomy requiring revision surgery. MRI findings were abnormal in 14 out of 28 cases; however, with the numbers available in our study no correlation to clinical outcome could be detected. CONCLUSION: OAT in osteochondritis dissecans of the talus was a safe procedure with good clinical results. As abnormal MRI finding was not necessarily diagnostically conclusive, MRI might be of limited value in postoperative follow-up. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Silent slipped capital femoral epiphysis in overweight and obese children and adolescents.

Abnormal loading of the hip in obese children may lead to anatomic alterations and an increased prevalence of slipped capital femoral epiphysis (SCFE). The aims of this study were to examine the hip motion in obese children and adolescents and to estimate the prevalence of SCFE in a subgroup of patients characterized by pathological clinical examination and/or pain in the knee or hip joint. A total of 411 individuals (196 males), mean age 14.5 ± 2.5 years (7.8-20.4), mean BMI of 32.9 ± 5.6 kg/m(2) (20.3-51.5, z score +2.65) who were consecutively admitted for an inpatient weight loss program were included in the study. Twenty-six percent of the patients had load-dependent and 11.7 % had load-independent pain in the knee joint. A total of 9.3 % had load-dependent and 4.7 % had load-independent pain in the hip joint. Two patients (0.5 %) underwent surgical treatment of SCFE prior to entry. A total of 18.2 % of the patients showed a reduced range of motion for hip flexion (<90°) and 18.5 % a pathological decreased internal rotation (<10°). Radiological evaluation of the hips in the clinically conspicuous subgroup (n = 54) revealed an abnormal head-neck ratio as a sign of prior silent slipped capital femoral epiphysis in 11 patients (20.4 % of the 54 patients, 2.7 % of total cohort). In conclusion, these data show a high prevalence of SCFE-like tilt deformities in a selected group of severely obese children. Mild deformation of the epiphysis at young age might be a major predisposing factor for the development of hip osteoarthritis in obese adults.

Analysis of failed surgery for patellar instability in children with open growth plates.

PURPOSE: Many surgical procedures have been proposed to treat recurrent patellar dislocation in children. In recent years, a more tailored approach considering the underlying pathology has been advocated. The aim of the study was to analyze a group of patients with recurrent patellofemoral instability after unsuccessful operative stabilization (Roux-Goldthwait procedure, lateral release, medial reefing or in combination) in childhood and adolescence. METHODS: A total of 37 children and adolescents with recurrent patellofemoral instability despite previous surgery were analyzed retrospectively. Radiographic examination included AP and lateral views to assess patella alta and limb alignment. MRI was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TTTG) distance. As a control group, 23 age- and sex-matched adolescents that were treated with a favorable outcome after medial reefing alone or combined with a Roux-Goldthwait procedure were analyzed. RESULTS: Severe trochlear dysplasia (type B-D according to Dejour) as detected on MRI scans was found significantly more often in the study group (89%) than in the control group (21%). No statistical difference of patellar height ratio (Insall-Salvati index) and TTTG distance between the two groups could be found. CONCLUSION: Of the measured parameters, only the incidence of trochlear dysplasia was increased. Trochlear dysplasia therefore seems to be a major risk factor for failure of operative stabilization of recurrent patellofemoral instability in children and adolescents. The results in children are in consensus with the literature in adults that a more tailored operative therapy including reconstruction of the MPFL and trochleaplasty has to be considered. LEVEL OF EVIDENCE: Retrospective study, Level III.

Dysplasia epiphysealis hemimelica: a case report with novel pathophysiologic aspects.

Dysplasia epiphysealis hemimelica (DEH) is a rare developmental disorder. The underlying pathophysiology is largely unclear. Its diagnosis is based on clinical findings and may be difficult due to its low incidence and close relationship to other disorders such as osteochondroma. We describe a 13-year-old boy who presented with a unilateral lesion of the left medial femoral condyle and left ankle. In addition to standard diagnostic tools such as radiographs and MRI, arthroscopy-guided biopsy was performed; histologic/immunohistochemical findings from cartilage-bone specimens confirmed the diagnosis and provided novel information toward a disease mechanism. The cellular phenotype of clustered chondrocytes exhibited characteristics of chondroprogenitor cells and terminally differentiated cells, suggesting dysregulation of resident progenitor cells. No other surgery was performed and during a 2 year period, we observed spontaneous ossification of the lesion associated with decreased joint impairment. Immunohistochemical analysis of the lesion provided a more accurate diagnosis and may contribute to unraveling potential novel mechanisms involved in its pathogenesis.

Femoral Derotational Osteotomies.

PURPOSE OF REVIEW: Femoral derotational osteotomies are performed to correct residual symptomatic increased femoral torsion in adolescents and adults. Typical indications are anterior knee pain caused by patellar maltracking and patellofemoral instability. There is still no consensus as to what the correct indication is and which surgical techniques lead to the best outcomes in performing a femoral derotational osteotomy. RECENT FINDINGS: Good early clinical outcomes have been reported. However, long-term studies and data on return to play are lacking. Surgery often is performed according to the surgeon's experience. There is no evidence to support decisions regarding surgical technique or level of osteotomy. Femoral derotational osteotomy is the treatment of choice in patients with symptomatic excessive anteversion and torsional malalignment of the femur. Multiple techniques have shown good clinical results with high patient satisfaction. Future studies however must focus on radiographic and clinical assessment to understand different subtypes of torsional deformity and its implication on operative therapy.

No Growth Disturbance After Trochleoplasty for Recurrent Patellar Dislocation in Adolescents With Open Growth Plates.

BACKGROUND: Trochlear dysplasia is the most important risk factor for patellofemoral instability among adolescents; therefore, trochleoplasty to reshape the trochlear groove is the treatment of choice for patients with high-grade trochlear dysplasia. However, in the presence of open growth plates, there is a potential risk of injury to the distal femoral growth plate and subsequent growth disturbance. As such, most authors do not recommend trochleoplasty for skeletally immature patients. The effect of trochleoplasty on femoral growth when performed before closure of the distal femoral physis remains unclear. HYPOTHESIS: For patients with open growth plates and an expected growth <2 years, trochleoplasty does not cause growth disturbance of the distal femur. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Eighteen consecutive adolescents (18 knees) with open physes and severe trochlear dysplasia underwent thin flap trochleoplasty. Pre- and postoperative radiographic examination included anteroposterior and lateral views to assess leg axis and patella alta. A preoperative radiograph of the left hand was performed to measure skeletal age. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove distance. Evaluation included pre- and postoperative physical examination with evaluation of leg length and leg axis, Kujala score, and Tegner activity score. RESULTS: The median age at the time of operation was 12.6 years (range, 12.2-13.3 years) for girls and 14.5 years (14.0-15.4 years) for boys. The mean follow-up after operation was 2.3 years after surgery (range, 2.0-3.0 years). At follow-up for all patients, the growth plates of the knee were closed. Impairment of growth of the distal femur was found neither clinically nor radiographically. No recurrent dislocation occurred. The median Kujala score improved significantly from 67 (range, 54-75) preoperatively to 89.5 (range, 78-96) at follow-up ( P < .01). The median visual analog scale showed significant pre- to postoperative improvement from 5 (range, 3-7) to 1 (range, 0-3) ( P < .01). The activity level according to the Tegner activity score did not change significantly. CONCLUSION: In this study, trochleoplasty as a treatment for patellofemoral instability of patients with open physes and an expected growth of not more than 2 years showed good clinical results without redislocation and with no growth disturbance. Therefore, for selected adolescent patients with high-grade trochlear dysplasia, trochleoplasty can be safely performed up to 2 years before the projected end of growth.

Impact of five different medial patellofemoral ligament-reconstruction strategies and three different graft pre-tensioning states on the mean patellofemoral contact pressure: a biomechanical study on human cadaver knees.

BACKGROUND: The medial patellofemoral ligament (MPFL) is the main stabiliser of the patella and thus mostly reconstructed in the surgical treatment of patellofemoral dislocation. The aims of this study were to gain a better understanding of the influence of altered MPFL graft-fixation locations and different graft pre-tensions on patellofemoral contact pressure. METHODS: Six human cadaveric knee joints were placed in a six-degree-of-freedom knee simulator. Mean PFCP (mPFCP) was evaluated in knee flexion of 0, 30 and 90° using a calibrated pressure-measurement system. After data assessment of the native knee joint, five MPFL reconstruction conditions were conducted: Anatomical double bundle; non-anatomical proximal patellar; non-anatomical distal patellar; non-anatomical proximal femoral; non-anatomical ventral femoral. The gracilis graft was fixed at a defined knee flexion of 30° and pre-tensioned to 2, 10 and 20 N. RESULTS: Kruskal-Wallis testing resulted in no mPFCP differences between the native and anatomical reconstruction states. Comparing the native and anatomical reconstruction states with the non-anatomical reconstruction states, no difference in the mPFCP both in knee extension (0°) (p>0.366) and in 30° knee flexion (p>0.349) was found. At 90° knee flexion, the following differences were identified: compared to the native knee state, the mPFCP increased after non-anatomical proximal femoral and non-anatomical ventral femoral reconstruction by 257% (p=0.04) and 292% (p=0.016), respectively. Compared to the anatomical reconstruction state, the mPFCP increased after non-anatomical proximal femoral reconstruction by 199% (p=0.042). DISCUSSION AND CONCLUSIONS: With respect to all study findings and to restore a physiological PFCP, we recommend using the anatomical footprints for MPFL reconstruction and a moderate graft pretensioning of 2-10 N.

Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft.

Reconstruction of the medial patellofemoral ligament (MPFL) has recently become a popular procedure for children and adolescents with patellofemoral instability. Nevertheless, high complication rates of up to 26% have been reported. The traditionally used technique requires patellar bone tunnels that may place the proportionately smaller patella at higher risk of fracture. Because of the adjacent physis of the femoral insertion, anatomic reconstruction of the MPFL has the risk of injury to the growth plate. This technical report therefore presents a technique for anatomic reconstruction of the MPFL in a skeletally immature population using a pedicled superficial quadriceps tendon graft, hardware-free patellar graft attachment, and anatomic femoral fixation distal to the femoral physis. The advantages of this technique include avoidance of bony patellar complications, an anatomically truer reconstruction, a single incision, and sparing of the hamstring tendons for reconstruction of any future ligamentous injuries.

Reconstruction of the Medial Patellofemoral Ligament: Clinical Outcomes and Return to Sports.

BACKGROUND: Recent studies have shown that medial patellofemoral ligament (MPFL) reconstruction using a standardized technique provides significant improvements in all outcome scoring systems, with low complication rates and good patient satisfaction. Although numerous studies have assessed clinical results, there is little published literature investigating return to sporting activities after reconstruction of the MPFL. PURPOSE: To demonstrate postoperative outcomes and the return-to-sports rate a minimum of 2 years after isolated MPFL reconstruction in a young patient cohort. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 2007 and 2010, a total of 72 isolated MPFL reconstructions (in 68 patients) were performed for recurrent patellar dislocation. Pre- and postoperative knee assessment included a thorough history of symptoms and a clinical examination consisting of crepitus, range of motion, patellofemoral pain, and patellar apprehension. Knee function was assessed using the Kujala score, International Knee Documentation Committee score, Tegner activity score, visual analog scale (VAS), and Activity Rating Scale (ARS). RESULTS: Of patients who participated in sports preoperatively (62/68 patients), 100% returned to sports after MPFL reconstruction; 53% returned at equal or higher levels, whereas 47% returned at lower levels. Fifty-four of 68 patients (79.4%) rated themselves as very satisfied or satisfied with the results. The median Kujala score improved significantly from 66 to 87.5 and the median International Knee Documentation Committee score from 60 to 79.8. The median VAS for pain score illustrated significant preoperative to postoperative improvement, from 4 to 2. Conversely, patients' activity levels according to the Tegner activity score dropped from 4.5 to 4, and the median Activity Rating Scale score dropped from 6 to 3. There was also a persistent instability rate of 10% as well as a slight loss of knee flexion in 24 of 72 knees. CONCLUSION: Reconstruction of the MPFL is a safe and effective treatment for patellofemoral instability without severe trochlear dysplasia and allows most patients to engage in regular sports activities 2 years postoperatively, at least at a recreational level. However, potential complications, such as persistent instability, pain, and loss of flexion, must be considered.

Combined trochleoplasty and medial patellofemoral ligament reconstruction for recurrent patellar dislocations in severe trochlear dysplasia: a minimum 2-year follow-up study.

BACKGROUND: Trochlear dysplasia is an important etiological factor for the development of patellofemoral instability. Because a dislocation of the patella as a result of trochlear dysplasia results in a traumatic disruption of the medial patellofemoral ligament (MPFL), a combined trochleoplasty and patellofemoral ligament reconstruction appears to be the most appropriate procedure to treat patients with severe trochlear dysplasia. HYPOTHESIS: Combined trochleoplasty and anatomic reconstruction of the MPFL will prevent redislocations of the patella and will lead to improved knee function. STUDY DESIGN: Case series; Level of evidence, 3. METHODS: Twenty-three consecutive patients (26 knees) with patellofemoral instability and severe trochlear dysplasia underwent combined trochleoplasty and anatomic reconstruction of the MPFL. Preoperative radiographic examination included anteroposterior and lateral views to assess patella alta. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and the tibial tubercle-trochlear groove (TT-TG) distance. Evaluations included the detection of cartilage injuries, preoperative and postoperative physical examinations, and scores for the visual analog scale (VAS), Kujala knee function, International Knee Documentation Committee (IKDC), activity rating scale (ARS), and Tegner activity scale. RESULTS: The mean age at the time of operation was 19.2 years (range, 15.4-23.6 years). The mean follow-up after operation was 2.5 years after surgery (range, 2.0-3.5 years). No recurrent dislocation occurred postoperatively. Kujala scores improved from 79 to 96, IKDC scores from 74 to 90, and VAS scores from 3 to 1. All improvements were highly statistically significant (P < .01). The activity level according to the Tegner activity scale and the ARS decreased but was not statistically significant (P = .06 and P = .21, respectively). There were 95.7% of the patients who were satisfied or very satisfied with the procedure. CONCLUSION: Combined anatomic reconstruction of the MPFL and trochleoplasty reliably improved the stability of the patellofemoral joint in patients with severe trochlear dysplasia and no or mild degenerative changes. In addition, the described procedure showed significant improvement of knee function and good patient satisfaction without any episode of redislocations of the patella.

Permanent patellar dislocation after a nonoperative treatment of recurrent dislocation of the patella because of trochlear dysplasia: a case report and review of the literature.

Patellar instability is a common knee injury in children and adolescents. After first-time dislocation, a nonoperative course is widespread. In cases of recurrent patellar dislocation, operative therapy is widely recommended. This case report shows the complicating history after a period of numerous patellar dislocations with primarily spontaneous reduction and a nonreducible dislocation at the follow-up 2 years after a nonoperative treatment.

Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents with open growth plates: surgical technique and clinical outcome.

BACKGROUND: Recurrent lateral patellar dislocation is a common knee injury in the skeletally immature adolescent. Because of the open physis, operative therapy in children is challenging. This study presents the outcomes of a minimally invasive technique for anatomic reconstruction of the medial patellofemoral ligament (MPFL) in children that respects the distal femoral physis. HYPOTHESIS: Anatomic reconstruction of the MPFL in children that maintains the distal femoral physis will prevent redislocation, preserve the distal femoral physis, and improve knee function. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-one consecutive patients with patellofemoral instability and open growth plates underwent anatomic reconstruction of the MPFL that maintained the distal femoral growth plate. Preoperative radiographic examination included AP and lateral views to assess patella alta and limb alignment. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TT-TG) distance. Evaluation included preoperative and postoperative physical examination, Kujala score, and Tegner activity score. RESULTS: The average age at the time of operation was 12.2 years (range, 10.3-13.9). The average follow-up after operation was 2.8 years after surgery (range, 2.0-3.6). No recurrent dislocation occurred, but 2 patients with high-grade trochlear dysplasia still had a positive apprehension sign. The Kujala score significantly improved from 72.9 (range, 37-87) preoperatively to 92.8 (range, 74-100) postoperatively (P < .01). The Tegner activity score decreased, but not significantly, from 6.0 (range, 3-9) preoperatively to 5.8 (range, 3-9) postoperatively (P = .48). CONCLUSION: Anatomic reconstruction of the MPFL that respects the distal femoral physis in skeletally immature patients is a safe and effective technique for the treatment of patellofemoral instability and allows patients to return to sports without redislocation of the patella.

Mid-term results after ultrasound-monitored treatment of developmental dysplasia of the hips: to what extent can a physiological development be expected?

The purpose of this study was to evaluate the radiological outcome after ultrasound-monitored treatment of developmental dysplasia of the hip at the age of 3 years. We retrospectively reviewed the findings of the second radiographic follow-up of 72 consecutive infants (mean age 31.3 months) with residual developmental dysplasia of the hip. Statistical analysis showed significant regression of acetabular index. Nevertheless, nine hips in seven children showed substantial residual dysplasia. Although remodelling of the acetabulum can be expected, there remains a risk of residual dysplasia. For this reason, radiographic follow-up of every once treated hip as well as the initially physiological contralateral hip is necessary.