Revision surgery for failed medial patellofemoral ligament reconstruction results in better disease-specific outcome scores when performed for recurrent instability than for patellofemoral pain or limited range of motion

Abstract

PurposeMedial patellofemoral ligament reconstruction (MPFL‐R) is an important treatment for recurrent patellar instability. Although complications such as redislocation, patellofemoral pain (PFP) and restricted knee range of motion have been reported, few studies have investigated the results of revision surgery for failed MPFL‐R. Thus, the aim of this study was to determine the results of the tailored revision surgery after considering the cause of the reconstruction failure. Materials and methodsBetween 2015 and 2019, 28 patients (male/female 9/19; age 26.2 ± 6.4 years) underwent revision surgery for failed MPFL‐R. The patients were grouped into the “recurrent instability” (SG1) group and “PFP” and/or “restricted range of motion” (SG2) group. Preoperatively, the clinical data, anatomical risk factor profile, and position of the femoral MPFL tunnel were determined for each patient. The Banff Patella Instability Instrument 2.0 (BPII 2.0) and numerical analogue scale (NAS 0–10) were administered preoperatively and at the final follow‐up for the subjective assessment of the PFP and knee joint function. ResultsOverall, the BPII 2.0 score improved from 28.8 ± 16.6 points preoperatively to 68.0 ± 22.7 points (p < 0.0001) postoperatively. SG1 exhibited an increase in the BPII 2.0 score from 28.9 ± 20.2 points to 75.7 ± 23 points (p < 0.0001). PFP decreased from 6.8 ± 2.4 to 1.6 ± 1.9 (p < 0.0001), while the knee joint function increased from 4.3 ± 2.5 to 8.8 ± 1.6 (p < 0.0001). In SG2, the BPII 2.0 score increased from 28.7 ± 12.6 points preoperatively to 57.7 ± 19.7 points (p = 0.0002) postoperatively and was thus significantly lower than that in SG1 (p = 0.038). The intensity of PFP decreased from 6.6 ± 3.0 preoperatively to 2.1 ± 1.9 postoperatively (p = 0.0006), while the subjective knee joint function improved from 3.2 ± 1.4 preoperatively to 7.6 ± 2.3 postoperatively (p < 0.0001). The differences between the groups were not significant. ConclusionTailored revision surgery for failed MPFL‐R significantly improves the patient‐reported disease‐specific quality of life. The study results indicate that patients undergoing revision surgery as a consequence of patellar redislocation appear to benefit more from revision surgery than those patients undergoing revision due to postoperative PFP and/or a limited knee joint range of motion. Level of evidenceLevel IV.

Trochlear Shape and Patient-Reported Outcomes After Arthroscopic Deepening Trochleoplasty and Medial Patellofemoral Ligament Reconstruction: A Retrospective Cohort Study Including MRI Assessments of the Trochlear Groove

“…In the current study, the BPII 2.0 score showed statistically significant and clinically relevant improvement, from 37.2 preoperatively to 74.3 postoperatively. This corresponds to the results from a case series of mixed surgeries after failed MPFL-R and a control group of similar procedures in nonrevision cases, where Zimmermann et al 46 found that the BPII 2.0 score increased from 28.6 to 68.0 in the revision group and from 43.8 to 75.5 in the control group. In a case series of open trochleoplasty and MPFL-R, Mengis et al 25 found that the BPII 2.0 score increased from 46.5 preoperatively to 80.4 postoperatively.…”

Outcomes After Derotational Distal Femoral Osteotomy for Recurrent Patellar Dislocations With Increased Femoral Anteversion: A Systematic Review and Meta-analysis

“…Therefore, an FAA >30 may be an appropriate indication for DDFO, and an FAA >25 should be considered with other factors. 21,34,39 Overtreatment should be avoided in cases of an increased TT-TG distance, as 3 studies 3,5,32 showed that the TT-TG distance decreased simultaneously to some extent after DDFO. DDFO should be performed first, followed by a careful evaluation of patellar tracking and stability to determine whether TTO should be performed at the same time.…”

Failure of isolated medial patellofemoral ligament reconstruction in children: Risk factors and management

“…Recurrent patellar dislocations were not observed during the follow-up, but three patients complained of temporary patellar subluxations. 37 The current series bears several obvious weaknesses linked to its retrospective and record-based nature and the absence of patient-reported outcome measure questionnaires. Failure rate may have been underestimated as recurrence may have occurred after the 2-year minimum follow-up threshold.…”

“…36 Trochleoplasties should also be deferred until skeletal maturity. Zimmermann et al 37 have reported on 28 MPFLR revisions (16 for recurrent instability, 12 for patella femoral pain or limited ROM) performed in young adults on average 31.2 months (range 6–72) from the primary surgery. Revision procedures performed included redo MPFLR, TTO, release of the MPFLR, deepening trochleoplasty and femoral de-rotation or varization osteotomy.…”

“…Recurrent patellar dislocations were not observed during the follow-up, but three patients complained of temporary patellar subluxations. 37 …”