Does the joint line matter in revision total knee replacement?

Abstract

We identified 148 patients who had undergone a revision total knee replacement using a single implant system between 1990 and 2000. Of these 18 patients had died, six had developed a peri-prosthetic fracture and ten had incomplete records or radiographs. This left 114 with prospectively-collected radiographs and Bristol knee scores available for study. The height of the joint line before and after revision total knee replacement was measured and classified as either restored to within 5 mm of the pre-operative height or elevated if it was positioned more than 5 mm above the pre-operative height. The joint line was elevated in 41 knees (36%) and restored in 73 (64%). Revision surgery significantly improved the mean Bristol knee score from 41.1 (SD 15.9) pre-operatively to 80.5 (SD 15) post-operatively (p < 0.001). At one year post-operatively both the total Bristol knee score and its functional component were significantly better in the restored group than in the elevated group (p < 0.01). Overall, revision from a unicondylar knee replacement required less use of bone graft, fewer component augments, restored the joint line more often and gave a significantly better total Bristol knee score (p < 0.02) and functional score (p < 0.01) than revision from total knee replacement. Our findings show that restoration of the joint line at revision total knee replacement gives a significantly better result than leaving it unrestored by more than 5 mm. We recommend the greater use of distal femoral augments to help to achieve this goal.

Restoration of the Distal Femur Impacts Patellar Height in Revision TKA

“…RTKA is challenging and a complex procedure compared to primary TKA. Several studies show restoration of joint line gives rise to better clinical and functional outcomes in RTKA [12,16,17]. Therefore, restoration of patellar height and joint line is of vital importance to achieve better clinical and functional outcomes in RTKA.…”

“…Several studies show restoration of the joint line gives rise to better knee and functional scores after RTKA [1,4,12,[15][16][17]. Therefore, it is critical to restore the joint line and patellar height during RTKA.…”

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“…If this corner was not identifiable, the most proximal point of the patellar tendon insertion was chosen (TT to the joint line of the knee: TTJL). The absolute perpendicular distance between the joint line and each anatomical landmark was measured and reported [1,2] .…”

“…Numerous methods, ranging from relative references, including "2 finger breadths from the tibial tubercle," to absolute distances, including "10 mm from the fibular styloid," have been described for joint line restoration [1] , yet a lack of consensus remains. Alternatively, the joint line of the knee can be estimated on a preoperative radiograph by measuring the distance from the joint line of the knee to either the medial epicondyle, fibular head, or tibial tubercle [2] . Anatomical studies have evaluated the distances from the femoral epicondyles, fibular head, and tibial tubercle to the joint line of the knee, in addition to the ratios of these absolute distances to femoral or tibial widths, compensating for sex and size differences.…”

Navigierte Implantation weichteilbalancierter Knieendoprothesen

“…Entschei dend zur Vermeidung von Instabilitäten zwischen 0° und 90°, den sogenannten "Midflexions"Instabilitäten, ist die akku rate Rekonstruktion der Gelenklinie [25]. Obwohl einige Autoren keine negativen Folgen bei Verlagerung der Gelenklinie beschrieben [33,39], wurde von Anderen ein Zusammenhang zwischen Gelenk linienverschiebung und femoropatellaren Beschwerden [21], erhöhten retropatella ren Scherkräften [19], schlechterem funk tionellen Ergebnis [27,28] sowie Bewe gungseinschränkungen [5] nachgewiesen.…”