Outcomes of Joint Preservation Procedures for Cartilage Injuries in the Hip: A Systematic Review and Meta-analysis

BACKGROUND: The detection and management of chondral injuries of the hip, especially in a younger patient population, may preempt joint degeneration. Although the outcomes of preservation techniques have been well described for other weightbearing joints, such as the knee, evidence for hip joint preservation after procedures such as microfracture and autologous chondrocyte implantation remains in its infancy. PURPOSE: To evaluate outcomes of joint preservation procedures in the hip, including the success rate and patient-reported outcomes (PROs). STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: This review was performed using the terms “hip arthroscopy,” “microfracture,” “autologous chondrocyte implantation,” “fibrin glue,” “osteochondral transfer,” and variations thereof in 5 electronic databases, yielding 325 abstracts. After the application of eligibility criteria, 19 articles were included. Weighted means were calculated for PROs, and pooled estimates were calculated for age, follow-up, chondral lesion size, and success of hip preservation procedures with a random-effects proportion meta-analysis. RESULTS: A total of 1484 patients (1502 hips) were identified across 19 studies (mean age, 38.0 ± 1.3 years; mean follow-up, 31.8 ± 9.6 months). Hip joint preservation techniques demonstrated a high success rate, ranging from 85.6% to 99.7%. The mean pooled chondral lesion size was 2.5 ± 0.3 cm(2) (95% CI, 1.9-3.0 cm(2)). Microfracture was the most frequent technique, utilized by 11 studies, and demonstrated an 89.6% success rate (95% CI, 82.4%-96.7%). The highest pooled success rate was exhibited by autologous membrane-induced chondrogenesis in 3 studies (99.7% [95% CI, 99.0%-100.0%]). All PROs demonstrated a statistically significant increase postoperatively, including the modified Harris Hip Score, Nonarthritic Hip Score, and Hip Outcome Score–Activities of Daily Living and Hip Outcome Score–Sports-Specific Subscale (all P < .05). The visual analog scale for pain also demonstrated a statistically significant decrease of 37.2% (P < .05). CONCLUSION: Hip preservation procedures demonstrate a high success rate, with microfracture representing the most frequently utilized cartilage preservation technique in the peer-reviewed literature. PROs significantly improved after surgery. Further investigation of hip preservation modalities with long-term follow-up is required to create evidence-based clinical recommendations and treatment algorithms.