Evaluation of different surgical methods in treating recurrent patella dislocation after three-dimensional reconstruction

Surgical treatment of patellar dislocation: A network meta-analysis of randomized control trials and cohort studies

Background

Currently, there are many surgical options for patellar dislocation. The purpose of this study is to perform a network meta-analysis of the randomized controlled trials (RCTs) and cohort studies to determine the better treatment.

Method

We searched the Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, clinicaltrials.gov and who.int/trialsearch. Clinical outcomes included Kujala score, Lysholm score, International Knee Documentation Committee (IKDC) score, redislocation or recurrent instability. We conducted pairwise meta-analysis and network meta-analysis respectively using the frequentist model to compare the clinical outcomes.

Results

There were 10 RCTs and 2 cohort studies with a total of 774 patients included in our study. In network meta-analysis, double-bundle medial patellofemoral ligament reconstruction (DB-MPFLR) achieved good results on functional scores. According to the surface under the cumulative ranking (SUCRA), DB-MPFLR had the highest probabilities of their protective effects on outcomes of Kujala score (SUCRA 96.5 %), IKDC score (SUCRA 100.0%) and redislocation (SUCRA 67.8%). However, DB-MPFLR (SUCRA 84.6%) comes second to SB-MPFLR (SUCRA 90.4%) in Lyshlom score. It is (SUCRA 70%) also inferior to vastus medialis plasty (VM-plasty) (SUCRA 81.9%) in preventing Recurrent instability. The results of subgroup analysis were similar.

Conclusion

Our study demonstrated that MPFLR showed better functional scores than other surgical options.

Classification and Segmentation Algorithm in Benign and Malignant Pulmonary Nodules under Different CT Reconstruction

Methods

The imaging data of 55 patients with chest CT plain scan in the Xuancheng People's Hospital were collected retrospectively. The data of each patient included lung window reconstruction, mediastinum reconstruction, and bone window reconstruction. The depth neural network and 3D convolution neural network were used to construct the model and train the classification and segmentation algorithm. The pathological results were the gold standard for benign and malignant pulmonary nodules. The classification and segmentation algorithms under three CT reconstruction algorithms were compared and analyzed by analysis of variance.

Results

Under the three CT reconstruction algorithms, the classification accuracy of pulmonary nodule density types was 98.2%, 96.4%, and 94.5%, respectively. The Dice coefficients of all nodule segmentation were 80.32% ± 5.91%, 79.83% ± 6.12%, and 80.17% ± 5.89%, respectively. The diagnostic accuracy between benign and malignant pulmonary nodules under different reconstruction algorithms was 98.2%, 96.4%, and 94.5%, respectively. There was no significant difference in the classification accuracy, Dice coefficients, and diagnostic accuracy of pulmonary nodules under three different reconstruction algorithms (all P > 0.05).

Conclusion

The depth neural network algorithm combined with 3D convolution neural network has a good efficiency in identifying benign and malignant pulmonary nodules under different CT reconstruction classification and segmentation algorithms.

Effects of Lateral Patellar Retinaculum Release for Recurrent Patella Dislocation: A Prospective Study

Purpose

Recurrent patellar dislocation (RPD) is the most common complication of patellar instability and the medial patellofemoral ligament (MPFL) reconstruction has become its reference treatment. Lateral patellar retinaculum (LPR) release used to be performed in association with MPFL reconstruction. The aim of this study was to investigate the added values of MPFL reconstruction plus LPR release for RPD.

Methods

After Institutional Review Board approval, RPD patients from October 2014 to April 2019 were randomly assigned into two groups (isolated MPFL reconstruction [Group I] and MPFL reconstruction plus LPR release [Group II]) and prospectively assessed until 12 months after surgery. Knee joints with flexion of 20° were scanned by a 64-row CT scanner. Congruence angle (CA), patella tilt angle (PTA), lateral patellofemoral angle (LPFA), tibial tuberosity-trochlear groove distance and patellar tilt with the quadriceps relaxed and contracted were measured. Knee function was assessed by Lysholm knee score and International Knee Documentation Committee (IKDC) score. Patients were followed up for at least 12 months.

Results

A total of 87 RPD patients (45 for Group I and 42 for Group II) were selected in this study. Preoperative clinical characteristics were not significantly different across groups. No serious complications were noted in either group. It was statistically insignificant between the two group patients in terms of postoperative patella associated measurements (P > 0.05 for all). The Lysholm score and IKDC score of Group I (84.5 ± 7.1 and 87.9 ± 7.2) were significantly less than that of Group II (89.7 ± 8.7 and 93.1 ± 7.7), which indicated the better knee function of Group II.

Conclusion

LPR release plus MPFL reconstruction provides additional benefits compared with isolated MPFL reconstruction in knee function. A combination of surgical treatments for RPD should be recommended.

Radiologic Measurements in the Assessment of Patellar Instability: A Systematic Review and Meta-analysis

Background:

Numerous diagnostic imaging measurements related to patellar instability have been evaluated in the literature; however, little has been done to compare these findings across multiple studies.

Purpose:

To review the different imaging measurements used to evaluate patellar instability and to assess the prevalence of each measure and its utility in predicting instability. We focused on reliability across imaging modalities and between patients with and without patellar instability.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

We performed a systematic review of the literature using the PubMed, SCOPUS, and Cochrane databases. Each database was searched for variations of the terms “patellar instability,” “patellar dislocation,” “trochlear dysplasia,” “radiographic measures,” “computed tomography,” and “magnetic resonance imaging.” Studies were included if they were published after May 1, 2009, and before May 1, 2019. A meta-analysis using a random effects model was performed on several measurements, comparing instability and control groups to generate pooled values.

Results:

A total of 813 articles were identified, and 96 articles comprising 7912 patients and 106 unique metrics were included in the analysis. The mean patient age was 23.1 years (95% CI, 21.1-24.5), and 41% were male. The tibial tubercle–trochlear groove (TT-TG) distance was the most frequently included metric (59 studies), followed by the Insall-Salvati ratio and Caton-Deschamps index (both 26 studies). The interobserver intraclass correlation coefficients were excellent or good for the TT-TG distance and Insall-Salvati ratio in 100% of studies reporting them; however, for the Caton-Deschamps index and Blackburne-Peel ratio, they were excellent or good in only 43% and 40% of studies. Pooled magnetic resonance imaging values for TT-TG distance (P < .01), Insall-Salvati ratio (P = .01), and femoral sulcus angle (P = .02) were significantly different between the instability and control groups. Values for tibial tubercle–posterior cruciate ligament distance (P = .36) and Caton-Deschamps index (P = .09) were not significantly different between groups.

Conclusion:

The most commonly reported measurements for evaluating patellar instability assessed patellar tracking and trochlear morphology. The TT-TG distance was the most common measurement and was greater in the patellar instability group as compared with the control group. In addition, the TT-TG, tibial tubercle–posterior cruciate ligament, and patellar tendon–trochlear groove distances were highly reproducible measurements for patellar tracking, and the Insall-Salvati ratio had superior reproducibility for assessing patellar height.

Arthroscopy-controlled medial reefing and lateral release for recurrent patellar dislocation: clinical, radiologic outcomes and complications

Background

Few studies have reported the clinical outcomes of the medial reefing procedure and lateral release with arthroscopic control of medial retinacular tension in patients with recurrent patellar dislocation. The purpose of this study was to investigate the clinical, radiologic outcomes and complications of arthroscopy-controlled medial reefing and lateral release.

Methods

Patients who underwent arthroscopy-controlled medial reefing and lateral release for recurrent patellar dislocation between November 2007 and June 2017 were retrospectively evaluated. The clinical outcome (Kujala score), radiologic outcome (congruence and patellar tilt angles), and complications were evaluated at final follow-up. The results were also compared with literature-reported outcomes of other surgical procedures for patellar dislocation.

Results

Twenty-five patients (mean age, 18.3 ± 4.8 years) were included in the study. The mean clinical follow-up period was 7.0 ± 2.5 (range, 3.8–12.2) years. The mean Kujala score was significantly improved from 54.7 ± 14.0 (range, 37–86) preoperatively to 91.0 ± 7.6 (range, 63–99) at a mean follow-up period of 7 years (P < 0.001). The radiologic results also significantly improved from 17.8° ± 5.9° to 6.8° ± 2.4° (P < 0.001) in the congruence angle and from 17.5° ± 8.2° to 5.6° ± 3.1° (P < 0.001) in the patella tilt angle at a mean follow-up period of 3.6 years. One patient developed a redislocation after a traumatic event, and two patients showed patellofemoral osteoarthritis progression.

Conclusions

Arthroscopy-controlled medial reefing and lateral release significantly improved the clinical and radiologic outcomes of the patients with recurrent patellar dislocation at a mean follow-up period of 7 years. The results of this study are comparable with the literature-reported outcomes of other surgical procedures for patellar dislocation.

Level of evidence

Level IV, retrospective therapeutic case series.

Femoral derotation osteotomy for recurrent patellar dislocation

PURPOSE

Excessive femoral internal torsion is an important risk factor for patellar dislocation. The aim of the present study was to estimate the effect of derotational osteotomy of the femur on the tibial tubercle trochlear groove (TTTG) distance or patellar tilt angle (PTA) and to report our clinical outcomes of recurrent patellar dislocation after femoral derotation osteotomy.

METHODS

A retrospective analysis of 16 patients (17 knees) with recurrent patellar dislocation treated by femoral derotation osteotomy in our department from January 2016 to February 2019 was carried out. The procedure was performed with supracondylar femoral derotation. A few procedures were combined with soft tissue procedures. Knee function was evaluated by using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS) score and patient satisfaction. Additionally, CT was used to assess the influence of femoral derotational osteotomy on TTTG distance and PTA.

RESULTS

The average femoral antetorsion angle before surgery was 33° (SD ± 5°), and the intraoperative correction angle was 23° (SD ± 4°). A total of 17 femoral derotation osteotomies in 16 patients with patellar instability [11 females, 5 males, aged 20.8 (range 15-41) years] were included in the study. No dislocation occurred within 26.5 months after follow-up (range 12-49 months). The IKDC score, Kujala score, Lysholm score and VAS score significantly improved. The preoperative TTTG distance was 15.63 mm (SD ± 2.07 mm), and it was 14.69 mm (SD ± 1.78 mm) at the follow-up. The PTA decreased from 26.35° (SD ± 6.86°) to 11.65° (SD ± 2.85°). The powers of TTTG and PTA measurements are 0.78 and 1.00, respectively and all of these differences were statistically significant.

CONCLUSIONS

Derotational osteotomy of the femur for the treatment of recurrent patellar dislocation can achieve good clinical results, including improved TTTG distance and PTA and improved knee function.

Comparative study of three different combination surgical methods for recurrent patella dislocation

PURPOSE

The effects of different combination of surgical techniques for recurrent patella dislocation (RPD) remain unclear. Thus, aim of this study was to investigate the surgical outcomes of different combination of surgical techniques for RPD.

METHODS

The clinical data of 79 patients with RPD from August 2014 to October 2016 were analysed retrospectively. Knee joint was assessed according to measurements of the congruence angle (CA), patellar tilt angle (PTA) and lateral patellofemoral angle (LPFA). Knee function was evaluated by Kujala patellofemoral score, Lysholm knee score and Tegner score. Patients were followed up by out-patient examination and telephone till October 2018.

RESULTS

Preoperative clinical characteristics were similar across groups. It was statistically insignificant among three groups in CA, PTA, LPFA and redislocation rate. In term of knee functions, the MPFL reconstruction and LPR release group had the highest score (Lysholm score: 91.82 ± 4.64, Kujala score: 94.22 ± 4.26, Tegner score: 5.80 ± 1.00, respectively) and the LPR release and MPR plication had the lowest score (Lysholm score: 78.10 ± 6.90, Kujala score: 80.91 ± 4.30, Tegner score: 4.98 ± 1.22, respectively).

CONCLUSION

Three combinations of surgical methods were similar in terms of postoperative joint congruence and redislocation rate, but MPFL reconstruction combined with LPR release is worthy to be promoted with the highest knee function scores.

Editorial Commentary: Repair or Reconstruct? Addressing Medial Patellofemoral Ligament Insufficiency in the Absence of Morphologic Abnormalities

The role of medial patellofemoral ligament (MPFL) repair versus reconstruction in the treatment of patellar instability continues to undergo debate. Repair of the ligament can be technically less demanding with fewer risks of morbidity, whereas reconstruction carries concerns of graft malpositioning or over-tensioning as well as the risk of patellar fracture. Studies directly comparing the 2 procedures in the setting of recurrent patellar instability have consisted of small series or low levels of evidence that inevitably include patients with concurrent morphologic risk factors such as tuberosity malalignment or patella alta, which are known factors that can influence the biomechanical behavior of the MPFL. Heterogeneity in patient-related risk factors and surgical techniques continues to pose limitations in allowing for direct comparisons between procedures. For the treatment of recurrent patellar instability in the setting of no (or concurrently addressed) morphologic abnormalities, MPFL reconstruction has become a common procedure and generally preferred approach. The superior outcomes associated with reconstruction over repair, however, should be qualified with the fact that attention to the critical details of the technique, including graft position and tension, is paramount to success when performing this procedure.

Recurrent Patellar Dislocations Without Untreated Predisposing Factors: Medial Patellofemoral Ligament Reconstruction Versus Other Medial Soft-Tissue Surgical Techniques-A Meta-analysis

PURPOSE

To provide a direct comparison between medial patellofemoral ligament (MPFL) reconstruction and the other medial patellofemoral soft-tissue surgeries in the restoration of the medial patellar restraint after lateral patellar dislocations in the absence of untreated predisposing factors such as high grade trochlear dysplasia, knee malalignment, patella alta or high tibial tubercle-trochlear groove distance.

METHODS

PubMed, Cochrane-library, Web of Science, and gray literature databases were searched to find all the relevant records. Study selection, data extraction, and risk of bias assessment were performed following the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Different techniques to treat lateral patellar dislocation in the absence of untreated predisposing factors were compared in terms of redislocation and complication rates, Kujala, Lysholm, International Knee Documentation Committee, and Tegner scores at the short-term (3 years) and long-term (>3 years) follow-up through meta-analyses.

RESULTS

Six studies involving 319 knees were included in the meta-analysis. The analyses of redislocation (0.7% vs 2.9%) and minor complication rates (12% vs 9%) showed no significant differences between MPFL reconstruction and other medial soft-tissue surgeries. Significant differences favoring MPFL reconstruction were documented in Kujala and Lysholm scores at short-term (8.6, P< .001; 10.9, P < .001) and long-term follow-ups (6.3, P = .02; 13.5, P < .001). No significant differences were found in the analyses of International Knee Documentation Committee (P = .10) and Tegner scores (P = .19). Level of evidence was low or very low.

CONCLUSIONS

MPFL reconstruction and medial patellofemoral soft-tissue surgery procedures were both effective in restoring the medial restraining forces preventing redislocation, but MPFL reconstruction provided better functional outcomes both at short-term and long-term follow-up. Thus, besides the treatment of predisposing factors, MPFL reconstruction seems to be, based on the results of this meta-analysis, a suitable strategy to restore the medial restraining function in the treatment of recurrent LPD.

LEVEL OF EVIDENCE

Level III (meta-analysis of randomized and nonrandomized comparative trials).

Surgical treatment is better than non-surgical treatment for primary patellar dislocation: a meta-analysis of randomized controlled trials

BACKGROUND

At present, the best treatment for primary patellar dislocation (PPD) has not been unified. Moreover, meta-analyses comparing the non-surgical and surgical treatments of PPD are lacking. Thus, we aimed to compare the clinical efficacy of surgical or non-surgical treatment of PPD.

METHODS

Randomized controlled studies of surgical and non-surgical treatments of PPD from 1966 to 2018 were retrieved from the following databases: PubMed, EMBASE, Cochrane Library, Wanfang Database, China Knowledge Network, Google Scholar, and Weipu Database. We screened for literature that met the inclusion criteria and extracted useful data for our meta-analysis.

RESULTS

Nine studies, involving 492 patients, met the inclusion criteria and were analyzed in this study. The recurrence rate of patellar dislocation in the surgical group was lower than that in the non-surgical group (P = 0.04]). Subgroup analysis according to the follow-up time showed that the Kujala score (P < 0.001) and lower recurrence rate of dislocation (P = 0.05) than the non-surgical group in the short term. Subgroup analysis according to surgical year showed that the surgical group get higher Kujala score (P < 0.001) and lower recurrence rate of dislocation (P = 0.01) than the non-surgical group in recent years.

CONCLUSION

Surgical treatment can provide better clinical results in a short period of time, and patients may achieve good results within 10 years owing to the advances in surgical techniques and instruments. Thus, we recommend surgical treatment as the preferred treatment for primary patellar dislocation.

Lateral retinacular release is not recommended in association to MPFL reconstruction in recurrent patellar dislocation

PURPOSE

Reconstruction of the medial patellofemoral ligament (MPFL) has become the gold standard for the treatment of the recurrent patellar dislocation (RPD). Lateral retinacular release can be performed in association with MPFL reconstruction, but the effect on outcomes is not clear. To evaluate the effect of lateral release on outcomes following MPFL reconstruction is the aim of this study. It is hypothesized that isolated MPFL reconstruction was not inferior to MPFL reconstruction and lateral retinacular release in terms of IKDC subjective score and patellar tilt (PT).

METHODS

Patients between ages 18 and 45 scheduled to undergo MPFL reconstruction without an associated bony procedure (tibial tubercle osteotomy or trochleoplasty) were randomized to isolated MPFL reconstruction or MPFL reconstruction (no LRR group) and arthroscopic LRR (LRR group). Evaluation criteria were subjective IKDC score as the primary outcome and PT evaluated with a CT-scan. PT was evaluated with the quadriceps relaxed (PTQR) and contracted (PTQC).

RESULTS

Of 43 patients included in the trial, 7 were lost of follow-up, 3 were not able to complete evaluation because of medical reasons, and 33 patients were evaluated with a minimum of 12 months and a median follow-up of 24 (12-60) months. The average subjective IKDC score was at 86 ± 20 (29-94) in the LRR group and 82 ± 15 (39-95) in the no LRR group (p = 0.45). The PTQR was at 22° ± 7° (13-37) in the LRR group and 21 ± 10 (4-37) in the no LRR group (n.s.). The PTQC was at 27° ± 9° (12-40) in the LRR group and 25 ± 12 (5-45) in the no LRR group (n.s.). No complications were noted in either group.

CONCLUSIONS

No significant differences were found in subjective IKDC score or patellar tilt based on the addition of an arthroscopic LRR to an MPFL reconstruction in patients with RPD not undergoing associated bony procedures. There is no indication to a systematic lateral retinacular release in association with MPFL reconstruction in the treatment of RPD.

LEVEL OF EVIDENCE

II.

Medial patellofemoral ligament reconstruction with or without tibial tubercle transfer is an effective treatment for patellofemoral instability

PURPOSE

The hypotheses were that medial patellofemoral ligament reconstruction (MPFLr) would improve the long-term symptoms of patellofemoral Instability (PFI) and control patellar tilt, based on computed tomography (CT), and that the addition of a TT transfer, when it is necessary, would not deteriorate the outcome. The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of a large series of MPFLr, either isolated or associated with a TT transfer.

METHODS

From 133 MPFLr with a minimum of 4 years postoperatively, three groups were defined: isolated MPFLr, MPFLr with tibial tubercle (TT) medialisation or MPFLr with TT medialisation and distalisation. IKDC and Kujala scores were evaluated. Patellar tilt was evaluated on the patient's preoperative and the last available radiograph, and on CT scan measurements performed preoperatively and at 6-month postoperatively.

RESULTS

The mean follow-up was 6.3 ± 1.7 years [4.1-10.3] and four patients reported recurrent patellar dislocation. Between pre and postoperative at last follow-up a significant improvement in IKDC and Kujala functional scores was observed (P < 0.01), with no difference between the three groups. Regarding patellar tilt, there were significant decreases in Laurin and Merchant angles and an improvement of the Maldague stage (P < 0.01). The CT analysis of patellar tilt also demonstrates a significant improvement of the patella tilt (P < 0.01). The control of the patella tilt was correlated with a good functional result (P < 0.01).

CONCLUSION

The MPFLr, whether isolated or associated with a TT transfer, provides good long-term clinical and radiological outcomes with a low rate of recurrence. The addition of a TT transfer, when necessary, results in the same good outcomes. This article provides a guide for surgeons evaluating PFI to choose the most appropriate procedure.

LEVEL OF EVIDENCE

IV.

Axial patellar engagement index and patellar tilt after medial patello-femoral ligament reconstruction in children and adolescents

BACKGROUND

The medial patello-femoral ligament (MPFL) is a major patellar stabiliser whose reconstruction in adults involves graft fixation within a femoral tunnel. In skeletally immature patients, in contrast, the graft is fixed to the soft tissues to allow normal growth. The primary objective of this prospective study was to perform computed tomography (CT) and magnetic resonance imaging (MRI) assessments of medium-term correction of patellar tilt and of the axial patellar engagement index (AEI) after a paediatric variant of MPFL reconstruction in skeletally immature patients.

HYPOTHESIS

MPFL reconstruction, performed alone or combined with other procedures in skeletally immature patients, decreases patellar tilt and improves the AEI.

MATERIAL AND METHODS

Eighteen children and adolescents with a median age of 14.6 years (range, 8-17 years) who underwent MPFL reconstruction on 20 knees were included in this prospective observational study. A double-strand gracilis tendon graft passed through the medial collateral ligament was used. MPFL reconstruction was performed alone in 13 knees and was combined with lateral retinaculum release, tibial tuberosity translation, and/or trochleoplasty in 7 knees. Patellar tilt and AEI values determined on preoperative and post-operative imaging studies with the quadriceps relaxed and contracted were compared. A physical examination was also performed.

RESULTS

From baseline to last follow-up after a mean of 43 months (range, 24-63 months), patellar tilt decreased from 20° preoperatively to 9° with the quadriceps relaxed and from 33° to 15.4° with the quadriceps contracted. The AEI increased from 0.78 at baseline to 0.93 at last follow-up. No dislocation or subluxation recurrences were recorded during follow-up.

DISCUSSION

The patellar tilt and AEI improvements seen after paediatric MPFL reconstruction confirm the study hypothesis. This is the first prospective study of patellar position in the axial plane as assessed by CT and MRI after paediatric MPFL reconstruction. In everyday clinical practice, 3D assessments of patellar tilt and the AEI should be performed to evaluate correction of the abnormalities.

LEVEL OF EVIDENCE

II, non-randomised prospective observational study.

Treatment of recurrent patellar dislocation via knee arthroscopy combined with C-arm fluoroscopy and reconstruction of the medial patellofemoral ligament

Recurrent patellar dislocations were treated via knee arthroscopy combined with C-arm fluoroscopy, and reconstruction of the medial patellofemoral ligaments. Between October 2013 and March 2017, 52 cases of recurrent patellar dislocation [27 males and 25 females; age, 16-47 years (mean, 21.90 years)] were treated. Arthroscopic exploration was performed and patellofemoral joint cartilage injuries were repaired. It was subsequently determined whether it was necessary to release the lateral patellofemoral support belt. Pre-operative measurements were used to decide whether tibial tubercle osteotomy was required. Medial patellofemoral ligaments were reconstructed using autologous semitendinosus tendons. Smith and Nephew model 3.5 line anchors were used to double-anchor the medial patellofemoral margin. On the femoral side, the medial patellofemoral ligament was fixed using 7-cm, absorbable, interfacial compression screws. All cases were followed for 1-40 months (average, 21 months). The Q angle, tibial tuberosity trochlear groove distance, Insall-Salvati index, patellofemoral angle, lateral patellofemoral angle and lateral shift were evaluated on X-Ray images using the picture archiving and communication system. Subjective International Knee Documentation Committee (IKDC) knee joint functional scores and Lysholm scores were recorded. Post-operative fear was absent, and no patellar re-dislocation or re-fracture was noted during follow-up. At the end of follow-up, the patellofemoral angle (0.22±4.23°), lateral patellofemoral angle (3.44±1.30°), and lateral shift (0.36+0.14°) differed significantly from the pre-operative values (all, P<0.05). Furthermore, IKDC and Lysholm scores (87.84+3.74 and 87.48+3.35, respectively) differed significantly from the pre-operative values (both, P<0.05). These findings suggest that, in the short term, recurrent patellar dislocation treatment via knee arthroscopy combined with C-arm fluoroscopy and reconstruction of the medial patellofemoral ligament was effective.