Lateral release and proximal realignment for patellofemoral malalignment. A prospective study of 40 knees in 36 adolescents followed for 1-8 years

Medial patellofemoral ligament reconstruction appears to be a better treatment than repair, proximal realignment, or conservative management for primary patellar dislocation: A network meta-analysis

BACKGROUND

The purpose of this study was to compare the functional outcomes and re-dislocation rates of medial patellofemoral ligament (MPFL) reconstruction, MPFL repair, combined proximal realignment (CPR), and conservative management for primary patellar dislocation by conducting a systematic literature search of the available studies. The hypothesis was that MPFL repair and MPFL reconstruction would be better options for treating primary patellar dislocation.

METHODS

Randomized controlled trials or prospective studies of primary patellar dislocation treated with MPFL reconstruction, MPFL repair, CPR, or conservative management were identified from the MEDLINE, EMBASE, and the Cochrane Library databases through December 31, 2021. A total of 626 patients met the prespecified inclusion criteria. The methodological quality of each study was assessed using a risk of bias table, Detsky quality index, and Newcastle-Ottawa Scale. The end-point data collected included comparisons of the mean in functional scores on knee outcomes scales and the number of patients who experienced re-dislocation. A network meta-analysis of the relevant literature was performed to investigate which treatment showed better outcomes.

RESULTS

In total, 10 trials were included in this study. There was no statistically significant difference in the subgroup analysis in terms of the functional outcomes among MPFL reconstruction, MPFL repair, CPR, and conservative management. However, MPFL reconstruction showed statistically significantly better outcomes than MPFL repair, CPR, or conservative management in terms of the re-dislocation rate. Additionally, surface under the cumulative ranking curve percentage showed that MPFL reconstruction had a lower probability of re-dislocation than MPFL repair even though there was no significant difference (0.24, 95% confidence interval: 0.02-2.91).

CONCLUSION

Using a network meta-analysis, this meta-analysis showed that there was no significant difference in functional outcomes in a subgroup analysis. In re-dislocation subgroup analysis, MPFL repair and MPFL reconstruction produced significantly better results than other treatments. Also, surface under the cumulative ranking curve percentage showed that MPFL reconstruction had a lower probability of re-dislocation than MPFL repair.

Editorial Commentary: From Lateral Release and Medial Plication to Complex Medial Patellofemoral Ligament Reconstruction Techniques: Medial Quadriceps Tendon Femoral Ligament Reconstruction Is the Most Anatomic Repair

Patella instability and dislocation are common in younger patients, and 1 in 5 patients are at risk of recurrent dislocations. Conservative treatment should be considered for first dislocations unless other concomitant injuries are present. Historically, lateral patella release and medial plication techniques were used for repair but have been superseded by medial patellofemoral ligament reconstruction. Overconstraint is a potential problem and often related to nonanatomic femoral tunnel position and graft tension, which could result in increased patellar contact pressures and graft failure. The medial quadriceps tendon-femoral ligament reconstruction technique (MQTFL) avoids patellar tunnels without the risk of patella fracture. When comparing medial patellofemoral ligament, MQTFL, and the combination of both techniques in a cadaver model, MQTFL resulted in less constraint with no differences for patellar contact pressures. Medial quadriceps tendon femoral ligament reconstruction is the most anatomic repair.

Long-term outcome after operative treatment of traumatic patellar dislocation in adolescents

OBJECTIVES

Retrospective evaluation of the long-term outcomes after surgical treatment of traumatic patellar dislocations in adolescents and identification of possible predictive factors of poor outcomes.

DESIGN

Retrospective clinical study.

SETTING

University Clinic, Level I Trauma Center.

PATIENTS

All 33 adolescents, with a mean age of 14.8 years, who were treated surgically after traumatic patellar dislocation between 1994 and 2006, were involved in this study.

INTERVENTION

Mini-open medial reefing and arthroscopic lateral release.

MAIN OUTCOME MEASUREMENTS

The clinical outcome was evaluated with the visual analogue scale, the Lysholm score, the Kujala score, and the Tegner activity level scale. On preoperative radiographs and magnetic resonance imaging scans, trochlear dysplasia and patella alta were assessed. The variables analyzed were sex, associated osteochondral injuries, the number of redislocations before surgery, and the number of redislocations after surgery.

RESULTS

At the mean follow-up of 9.8 years, the mean Lysholm score was 82.6, the mean Kujala score was 84.4, the mean Tegner activity level was 4.8, and the mean visual analogue scale was 0.2. We found no significant differences in the subgroups regarding functional outcomes. Fifteen patients with patella alta and 4 patients with trochlear dysplasia were assessed radiologically. Redislocations after surgery were observed in 4 patients, 2 of them were female patients who exhibited quadriceps angles requiring tibial tubercle osteotomy to be performed after maturation.

CONCLUSIONS

The techniques of mini-open medial reefing and lateral release demonstrate a good functional long-term outcome and effectively prevent recurrent instability. The major predictive factor for poor outcomes and redislocations is an inadequately addressed pathology.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical and electromyographic results of proximal and distal realignment procedures in young patients with recurrent patellar dislocations

BACKGROUND

Until now, no study has been published about the electromyographic changes in the extensor apparatus after the Green procedure for proximal realignment in young patients with recurrent patellar dislocations. This electromyographic study was performed to analyze imbalances between the vastus medialis and vastus lateralis muscles after different patellar realignment procedures.

HYPOTHESIS

Surgical proximal realignment leads to electromyographic changes in the extensor apparatus of the knee and to imbalances between the vastus medialis and vastus lateralis muscles.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 28 knees of 25 patients, with a mean age of 15 years, were treated operatively for recurrent patellar dislocations. The mean follow-up was 6.3 years. Depending on the type of surgical intervention, the patients were assigned to 3 different groups: the patients of group 1 underwent only the Green vastus medialis obliquus (VMO) advancement, group 2 was treated with a combination of the Green proximal and the Roux-Goldthwait distal realignment, and group 3 was treated with a combination of the Green proximal realignment and an additional tubercle transfer. All patients underwent clinical, radiological, and electromyographic examinations. The muscle activities of a healthy control group without patellar dislocations were used for comparison.

RESULTS

A combination of the Green procedure and tubercle transfer led to significantly better clinical results and a lower number of redislocations (P < .05) compared with patients who underwent only the Green proximal realignment. While ascending or descending stairs, the ratio between the electromyographic activities of the vastus medialis and vastus lateralis muscles in groups 1 and 2 was significantly smaller compared with the control group (P < .02). Only the electromyograms of group 3 revealed a balanced extensor apparatus during loading with comparable activities of the vastus medialis and vastus lateralis muscles and no significant difference to the control group (P = .37).

CONCLUSION

Our electromyographic investigations showed the importance of the vastus medialis in the pathogenesis of malalignment of the extensor mechanism. The Green VMO advancement without tibial tubercle transfer is not able to balance the activities of the vastus medialis and vastus lateralis muscles and cannot be recommended for further use.

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.

Long-term functional outcome after lateral patellar retinacular release in adolescents: an observational cohort study with minimum 5-year follow-up

BACKGROUND

Lateral patellar retinacular release has been recommended for patients with patellar tilt, tight lateral retinaculum, patellar subluxation, patellar dislocation, and patellofemoral pain. Studies of long-term outcomes after lateral release are limited, especially for differing indications.

HYPOTHESIS

Adolescents do well after lateral retinacular release in the 5- to 22-year time frame.

METHODS

Patients having undergone lateral retinacular release between the years of 1981 and 1999 were contacted. Evaluation was by the Cincinnati and Lysholm scales and by level of satisfaction and need for reoperation.

RESULTS

One hundred forty knees were studied. Mean age at operation was 15.4 years (SD, 2.7 years). Average follow-up was 8.5 (SD, 4.1 years; range, 5.2-22.5 years). Twenty-five patients had needed reoperation, indicating failure of the index operation. Kaplan-Meier survivorship was 78% at 15 years. Cincinnati and Lysholm scores indicated well-functioning knees in those not requiring reoperation. Overall satisfaction improved as time from operation increased. Comparisons were made between the group requiring reoperation and those who did not. Focus was placed on knees with patellar maltracking or tilt versus patellar instability and between males and females. No differences were found among groups for reoperation rate, level of satisfaction, average Lysholm score, or average Cincinnati score. There were no differences in demographics or outcome measures between patients with patellar instability and those with tilt. Instability patients trended toward higher reoperation rates than did tilt patients, but the difference was not significant. There were no differences between males and females.

CONCLUSION

The majority of patients are satisfied with their knee 5 to 22 years after lateral patellar retinacular release and scored well on questions rating knee health and function.

Treatment of recurrent patellar instability with a modification of the Roux-Goldthwait technique

Recurrent instability of the patella may be a significant disability in the childhood and adolescent population. Numerous surgical procedures to address this instability have been described, with variable outcome. This has led to considerable confusion in the literature as to how to treat patellofemoral problems in children. This study retrospectively reviews 30 knees in 20 patients with chronic recurrent patellar instability who were treated with a modified Roux-Goldthwait technique including the release of contracted lateral structures by a single surgeon over a 13-year period, with an average of 6.2 years follow-up. By Insall's criteria, 26 knees had an excellent result, 3 good result, and 1 fair result. Ten patients evaluated using a dynamometer showed that strength achieved in the operated leg was greater than 90% in 8 patients and greater than 80% in 2 patients. Here, we report upon a single operation to treat patellar instability performed in the pediatric population with consistently excellent results.