Background

Isolated antero-medial osteoarthritis (AMOA) of the knee is a distinct pattern of arthritis. Medial arthritis of the knee in select patients can be managed with uni-compartmental arthroplasty (UKA), with studies showing shorter hospital stay, faster rehabilitation and reduced medical complications in the post-operative period compared to TKA. However, the prevalence of AMOA in Indian patients with osteoarthritis of the knee is unknown. The aim of this study was to evaluate the prevalence of AMOA in patients undergoing primary TKA for OA.

Methods

This was a prospective evaluation of 2518 knees in 1936 patients who were selected for primary TKA. Pre-operative radiographs were screened based on the Oxford UKA Radiological decision aid and diagnosis of AMOA was established. All 2518 knees underwent primary total knee arthroplasty and cases of AMOA were confirmed intra-operatively based on ACL integrity, lateral compartment wear and medial compartment wear pattern. Cases with AMOA arthritic wear pattern were considered amenable for UKA if radiographs showed intact lateral joint space, intra-operatively those with intact and functional ACL, acceptable patellofemoral wear (Outerbridge I–II).

Results

We report a prevalence of 46.94% of AMOA, who were amenable for UKA. Obese patients were more likely to have a damaged or non-functional ACL and more likely to have a high degree of wear, not amenable for UKA (p < 0.05). Non-functional ACL was associated with higher prevalence of posterior extension of arthritic wear.

Conclusion

This study demonstrated a high prevalence (46.94%) of antero-medial osteoarthritis (AMOA), amenable for UKA. Patient selection is important for improving outcomes after TKA or UKA. Future studies are warranted to compare outcomes of both UKA and TKA in patients with isolated AMOA of the knee.

中文翻译：

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接受初次全膝关节置换术的印度患者中孤立性前内侧骨关节炎 (AMOA) 的患病率很高

背景

膝关节孤立性前内侧骨关节炎 (AMOA) 是一种独特的关节炎模式。部分患者的膝关节内侧关节炎可以通过单间室关节置换术 (UKA) 进行治疗，研究表明与 TKA 相比，住院时间更短、康复更快、术后并发症更少。然而，印度膝骨关节炎患者中 AMOA 的患病率尚不清楚。本研究的目的是评估因 OA 接受初次 TKA 的患者中 AMOA 的患病率。

方法

这是对 1936 名被选择进行初次 TKA 的患者的 2518 个膝关节的前瞻性评估。根据牛津 UKA 放射学决策辅助工具对术前 X​​ 光片进行筛选，并确定 AMOA 的诊断。所有 2518 个膝关节均接受了初次全膝关节置换术，术中根据 ACL 完整性、外侧间室磨损和内侧间室磨损模式确认了 AMOA 病例。如果 X 光片显示外侧关节间隙完整、术中 ACL 完整且功能正常、髌股磨损可接受（Outerbridge I-II），则具有 AMOA 关节炎磨损模式的病例被认为适合 UKA。

结果

我们报告 AMOA 的患病率为 46.94%，他们适合接受 UKA。肥胖患者更有可能出现 ACL 受损或无功能的情况，并且更有可能出现高度磨损，不适合 UKA ( p  < 0.05)。非功能性 ACL 与关节炎磨损后延伸的发生率较高相关。

结论

这项研究表明前内侧骨关节炎 (AMOA) 的患病率很高 (46.94%)，适合 UKA。患者选择对于改善 TKA 或 UKA 术后的预后非常重要。未来的研究有必要比较 UKA 和 TKA 对膝关节孤立性 AMOA 患者的结果。