外侧半月板切除术后膝关节周围骨密度的改变

Changes in bone mineral density around knee joint after lateral meniscectomy

目的:观察外侧半月板切除术后膝关节周围骨密度的改变。方法:选择1984/2002年唐山市第二医院骨科、华北煤炭医学院附属医院以及开滦医院施行外侧半月板切除术的患者128例,其中男64例,女64例;年龄14～68岁。实验分组:根据术后时间分为:0～1年组32例,2～4年组32例,5～10年组30例和11～17年组34例,设健侧为对照组。方法及评估:应用双能X射线骨密度仪分别测量膝关节周围6个感兴趣区骨密度(6区:以胫骨上端松质骨区腓骨小头水平面作为参考平面,在胫骨外、内侧分别作0.8cm×0.8cm的感兴趣区,称为R1,R2。以股骨下端股骨髁间切迹水平面作为参考平面,在股骨内外侧髁分别作0.8cm×0.8cm的感兴趣区,称为R3,R4。在胫骨上端密质骨区胫骨平台外、内侧软骨下分别作1.4cm×0.4cm的感兴趣区,称为R5,R6)并计算出外侧、内侧骨密度的变化值,用均数百分数±标准差表示。结果:128例患者全部进入结果分析。①在术后17年内胫骨上端外内侧(R56)密质骨骨密度变化值:0～17年术侧均明显高于健侧[0～1年:(-10.20±13.62)%,(-22.80±13.54)%;2～4年:(-8.87±15.05)%,(-17.82±11.06)%;5～10年:(5.06±18.64)%,(-8.62±12.97)%;11～17年:(6.17±14.56)%,(-7.86±10.73)%,t=2.41～8.95,P<0.05]。②5～17年胫骨上端外内侧(R12)松质骨骨密度变化值:5～17年术侧均明显高于健侧[5～10年:(12.15±22.48)%,(0.40±14.40)%,11～17年:(8.16±13.37)%,(-4.90±10.44)%,t=2.31,2.40,P<0.05]。③11～17年股骨下端近膝关节区外内侧(R43)骨密度变化值:术侧明显高于健侧[(4.43±13.70)%,(-4.68±17.68)%,t=2.17,P<0.05]。结论:外侧半月板切除术后可引起膝关节周围骨密度的改变,发生适应性的骨重构:胫骨上端密质骨区最早发生,胫骨上端松质骨区其后发生,股骨下端近膝关节区最后发生。

AIM： To study the redistribution of bone mineral density （BMD） around the knee joint after lateral meniscactomy （LMT）. METHODS： A total of 128 patients who had undergone LMT were selected from the Department of Orthopaedics, the Second Hospital of Tangshan, Affiliated Hospital of North China Coal Medical College and Kailuan Hospital from 1984 to 2002, including 64 males and 64 females, with an age of 14-68 years. Grouping methods： Four groups were divided respectively according to the time after LMT： 0-1 year （n =32）, 2-4 years （n =32）, 5-10 years （n =30）, and 11-17 years （n =34）. And healthy knee joints were taken as control group. Periarticular BMD of six ROIs （regions of interest） at meniscectomized knee and healthy contralateral knee was measured by DXA （dual energy X-ray absorptiometry）： R1, R2 （0.8 cm × 0.8 cm） in the tibia between lateral side and medial side, taking capitulum fibulae in cancellous bone district of superior tibia as reference plane; R3, R4 （0.8 cm × 0.8 cm） in the femur between lateral side and medial side, taking intercondylar notch of inferior femur as reference plane; R5, R6 （1.4 cm × 0.4 cm） in the dense bone of superior tibia between lateral side and medial side. The BMD distribution change of related ROIs between medial and lateral of same knee was compared and analyzed, expressing as mean percentage ＋ standard deviation. RESULTS： All 128 patients were involved in the result analysis.（1）The change percentage of BMD in the cortical bone of the proximal tibia （R5-6） was increased obviously compared with that of healthy legs during the period of 17-year follow-ups [0-1 year： （-10.20±13.62）%, （-22.80±13.54）%; 2-4 years： （-8.87±15.05）%, （-17.82±11.06）%; 5-10 years： （5.06±18.64）%, （-8.62±12.97）%; 11-17 years： （6.17±14.56）%, （-7.86±10.73）%, t =2.41-8.95, P 〈 0.05].（2）The change percentage of BMD in the cortical bone of the proximal tibia （R1-2） was increased apparently compared with healthy legs during 5-17 years after LMT [5-10 years： （12.15±22.48）%, （0.40±14.40）%; 11-17 years： （8.16±13.37）%, （-4.90± 10.44）%, t =2.31, 2.40, P 〈 0.05].（3）The change percentage of BMD in the distal femur adjacent to knee joint （R3-4） was higher obviously than that of healthy legs [（4.43±13.70）%, （-4.68±17.68）%, t =2.17, P 〈 0.05]. CONCLUSION： The redistribution of BMD, and adaptive bone remodel around the knee joint may take place after LMT. It occurs in the cortical bone of the proximal tibia at first, then in the cortical bone of the proximal tibia and in the distal femur adjacent to knee joint at last.