2017 ISAKOS Biennial Congress ePoster #1702

 

Anteromedialization Tibial Tubercle Osteotomy with Medial Reefing for Patellar Dislocation Due to Trochlear Dysplasia: Is it Enough?

David Y. Ding, MD
Alan Zhang, MD, San Francisco, CA UNITED STATES
Michael Leathers, Marina Dl Rey, CA UNITED STATES
Liane Miller, MD, San Francisco, CA UNITED STATES
Tiana Woolridge, BA, San Francisco, CA UNITED STATES
Brian Feeley, MD, San Francisco, CA UNITED STATES
Christina R. Allen, San Francisco, CA UNITED STATES
C. Benjamin Ma, MD, San Francisco, CA UNITED STATES

University of California, San Francisco Medical Center, San Francisco, California, UNITED STATES

FDA Status Not Applicable

Summary

At mid-term follow up, tibial tubercle osteotomy with medial reefing reliably prevented repeat episodes of patellar instability in 86.5% of patients with trochlea dysplasia while reducing pain and improving function.

Abstract

Introduction

Recurrent patellar instability can be a source of continued pain and functional limitation in the young, active patient population. Instability in the setting of an elevated tibial tubercle-trochlear groove (TT-TG) distance can be effectively managed with a tibial tubercle osteotomy with or without an associated medial patellofemoral ligament (MPFL) procedure such as reefing or reconstruction. However, there have not been any previous investigations analyzing the effects of anteromedialization tibial tubercle osteotomy and MPFL reefing on patellar instability in the setting of trochlea dysplasia. While a reconstruction may provide additional stability, it has risks such as graft harvest morbidity, patella fracture, increased constraint, and increased operating time.

Methods

A retrospective chart review was performed to identify patients who had undergone MPFL reefing and anteromedialization tibial tubercle osteotomy for chronic patellofemoral instability at a single institution with minimum 1 year follow up. Patient demographic information including age at time of surgery, gender, body mass index (BMI), tibial tubercle – trochlear groove (TT-TG) distance, and grade of trochlear dysplasia were collected along with relevant operative data. Postoperatively, redislocations events as well as KOOS, WOMAC, and Kujala scores were collected, and patient satisfaction was ascertained by asking whether or not they would have the procedure again.

Results

37 knees from 31 patients (23 females) with a mean follow-up time of 3.8 years (range 1-8.9) were included. The mean age was 28.8 years (14-45 years), BMI 24 kg/m2 (range 20-38), preoperative TT-TG 18.9 mm (8.4-32.4 mm). The most common concomitant procedure was a lateral release in 26 knees. 2/37 knees were classified as low-grade trochlear dysplasia (Dejour A) and 35/37 as high-grade trochlear dysplasia (Dejour B, C, D). At final follow-up, patients reported mean KOOS pain score 86.4, KOOS symptoms 79.8, KOOS ADL’s 93.9, KOOS sports 74.3, KOOS QoL 61.9, and Kujala score 81.3. Patient satisfaction was rated on average as 8.3/10 and 23/31 (74%) stated that they would have the procedure again. 5/37 (13.5%) suffered recurrent patella instability and 2 knees required revision stabilization. 8/37 knees (22%) underwent subsequent hardware removal.

Conclusion

At mid-term follow up, anteromedialization tibial tubercle osteotomy with medial reefing reliably prevented repeat episodes of patellar instability in 86.5% of patients with trochlea dysplasia while reducing pain and improving function.