Summary

Patients undergoing ACLR by high-volume surgeons experience a broader range of treatment options for cartilage injuries, and those operated on at high-volume clinics have increased odds for debridement and reduced odds for microfractures and non-surgical treatments compared to low-volume clinics.

Abstract

Background

Concomitant cartilage lesions are commonly found during primary anterior cruciate ligament reconstruction (ACLR). Various surgical options for cartilage injuries include debridement, microfractures, osteochondral autograft transplantation (OAT), and autologous chondrocyte implantation (ACI), each with their advantages and limitations. However, factors influencing the surgeon’s choice of cartilage treatment at primary ACLR remain unclear.

Purpose

To investigate the influence of surgical volume on the treatment of cartilage lesions during primary ACLR, and to examine the impact of various patient-, injury-, and surgery-related factors.

Methods

Prospectively collected data in the Swedish National Knee Ligament Registry were used to retrospectively study patients with cartilage lesions who underwent primary ACLR with autograft in 2008-2022. Surgeons and clinics were categorized as high- or low-volume, based on total caseload volume and annual volume (high-volume surgeons: =50 ACLRs and =29 ACLRs/year, high-volume clinics: =500 ACLRs and =56 ACLRs/year). Cartilage lesions were treated with debridement, microfractures, other methods (OAT, ACI, or unspecified) or non-surgically. Multivariable regression analyses assessed factors influencing the treatment (non-surgical/debridement/microfracture) of isolated, focal cartilage injuries. These were adjusted for patient age, sex, pivoting sports injury, meniscal tears, time to surgery, surgery year, cartilage injury type (location, surface area =2 cm2, and International Cartilage Repair Society (ICRS) 3-4), and surgeon and clinic volume. Results were presented as the odds ratios (OR) with 95% confidence intervals (CI).

Results

Among 11,729 patients with cartilage lesions at ACLR, 17.9% underwent debridement, 7.1% had microfractures and 1.4% received other treatments. ACLRs were performed by 284 surgeons at 89 clinics (high-volume: 117 surgeons and 30 clinics). More severe cartilage injuries were seen among patients treated by high-volume surgeons (area =2 cm2: 45.2% vs. 27.9%, ICRS 3-4: 25.6% vs. 20.3%) and at high-volume clinics (area =2 cm2: 43.5% vs. 34.9%, ICRS 3-4: 26.8% vs. 20.8%) (all p<0.001). Lesions to the medial femoral condyle were the most common among all surgical volume groups (67.0-68.9%), but high-volume surgeons/clinics reported more injuries in the lateral compartment and trochlea (all p=0.016). High-volume surgeons had more experience with debridement (81.2% vs. 61.0%), microfractures (78.6% vs. 43.3%), and other methods (32.5% vs. 12.3%) during ACLR compared to low-volume surgeons (all p<0.001). No significant differences were found between clinics. Adjusted logistic regression analyses showed high-volume clinics had higher odds of performing debridement (OR 1.36, 95%CI 1.19-1.55, p<0.001), while odds of microfractures (OR 0.71, 95%CI 0.57-0.88, p=0.002) and non-surgical treatment (OR 0.84, 95%CI 0.74-0.95, p=0.005) were lower. Surgeon volume did not influence treatment options. Age >30, ICRS 3-4 and more recent year of surgery increased odds of debridement (all p<0.001), while delayed surgery =2 years decreased it (p=0.032). Lesions in the lateral compartment and trochlea, area =2 cm2 and delayed surgery =3 months decreased odds of microfractures (all p<0.01). ICRS 3-4 significantly increased odds for microfractures (OR 71.9, 95%CI 52.2-99.1, p<0.001).

Conclusion

High-volume surgeons were more experienced in various treatments, but clinic routine influenced treatment strategies. Even though several confounders were considered, high-volume clinics performed more debridement and less microfractures and non-surgical treatments compared to low-volume clinics at primary ACLR.