Refixation of Large Osteochondral Fractures After Patella Dislocation Shows Better Mid- to Long-Term Outcome Compared With Debridement

Abstract

Objective: The purpose of this study was to compare results of osteochondral fractures (OCF) after first-time lateral patella dislocation, when either refixation or debridement was performed in a mid- to long-term follow-up and to analyze redislocation and reintervention rates.

Design: Fifty-three consecutive patients with OCF were included in this retrospective comparative study. Indication for refixation was presence of subchondral bone at the fragment. Thirty-six OCF were located at the patellar surface, and 17 at the lateral condyle of the distal femur. Refixation was performed in 28 patients while 25 patients underwent removal and debridement. Mean follow-up was 8.9 years (±4.4, range 2.0-16.7 years). For assessment of clinical outcome, the International Knee Documentation Committee (IKDC) Score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score were used. Redislocation rate and further surgical interventions within follow-up were evaluated.

Results: All clinical scores in the refixation group yielded significantly better results at mid- to long term follow-up (IKDC P < 0.001, KOOS P = 0.006, Lysholm P = 0.001). Significantly more surgical reinterventions were necessary after debridement (48% vs. 7.1%, P = 0.001). The overall redislocation rate in cases with medial reefing as single stabilizing procedure was 43.3%.

Conclusions: Refixation of OCF after lateral patella dislocation shows improved clinical outcome at mid- to long-term follow-up compared with debridement. Therefore, effort to try fragment refixation is recommended. Redislocation rate is high without proper restoration of patellofemoral instability.

Keywords: medial reefing; osteochondral fracture; patella dislocation; redislocation; refixation.

Figure 1.

Magnetic resonance imaging with acute osteochondral fracture (OCF) on the lateral femoral condyle with displaced fragment (sagittal view, PD FSE [proton density fast spin echo] sequence).

Figure 2.

(a) Osteochondral fragment deriving from lateral femoral condyle (same patient as shown in magnetic resonance imaging, Fig. 1 ). (b) Intraoperative situs of same osteochondral fragment after refixation with 3 biodegradable pins (Ethipins 1.3 mm).

Figure 3.

Magnetic resonance imaging after refixation of osteochondral fracture (OCF), 5-month postoperative (sagittal view, PD FSE [proton density fast spin echo] sequence).

Figure 4.

Boxplot of outcome scores of patients with mid- to long-term follow-up (>5 to 16 years) (range, median, 95% confidence interval). KOOS = Knee Injury and Osteoarthritis Outcome Score; IKDC = International Knee Documentation Committee; ADL = activities of daily living; Sport/Rec = sports and recreation; QoL = quality of life.