Jai-Gon Seo

Operative Treatment of Primary Synovial Osteochondromatosis of the Hip

BACKGROUND Primary synovial osteochondromatosis of the hip, a rare benign condition characterized by multiple intra-articular osteochondral loose bodies and synovial hyperplasia, may result in mechanical symptoms and degenerative arthritis if untreated. The purpose of this study was to report the results of arthrotomy alone or combined with anterior dislocation of the hip to perform synovectomy and removal of loose bodies in patients with this condition. METHODS We retrospectively reviewed a consecutive series of twenty-one patients (twenty-one hips) with primary synovial osteochondromatosis of the hip treated with open surgical débridement. On the basis of the extent of extra-articular involvement as seen on preoperative magnetic resonance imaging, eight of the twenty-one patients underwent synovectomy and removal of loose bodies following anterior dislocation of the hip and thirteen underwent the same procedure with arthrotomy alone. At a mean of 4.4 years postoperatively, the patients were assessed clinically and radiographically with special attention to disease recurrence, osteoarthritis progression, and surgical complications. RESULTS The mean Harris hip score for the entire series of patients improved from 58 points preoperatively to 91 points at the time of the latest follow-up. Eighteen of the twenty-one patients had a good or excellent clinical result, and seventeen patients were satisfied with the result of the surgery. The clinical scores, patient satisfaction scores, and radiographic grades of osteoarthritis at the time of the latest follow-up did not differ significantly between the group treated with dislocation and the group treated without dislocation. Symptomatic disease recurred in two of the thirteen hips treated with arthrotomy alone and in none of the hips that had undergone dislocation. However, the surgical complication rate was higher in the group treated with dislocation than it was in the group treated without dislocation (p = 0.042). While patients with some signs of mild osteoarthritis at the initial procedure had a higher rate of osteoarthritis progression, severe osteoarthritis requiring arthroplasty had developed in only one patient at the time of follow-up. CONCLUSIONS At a mean of 4.4 years postoperatively, we found that open synovectomy and removal of loose bodies for the treatment of primary synovial osteochondromatosis of the hip is a reliable procedure that can effectively relieve symptoms. Our results also indicated that synovial osteochondromatosis may recur in patients with extensive involvement who are treated with synovectomy alone without dislocation of the hip; however, surgical complications are more likely to occur in patients managed with anterior dislocation of the hip and synovectomy.

Variability in Femoral Component Rotation Reference Axes Measured During Navigation-Assisted Total Knee Arthroplasty Using Gap Technique

The basic objective in total knee arthroplasty is to achieve the correct amount of femoral component rotation, and this can be achieved either with a measured resection technique or indirectly with a flexion/extension gap equalization technique. We studied variability in the reference axes (posterior condylar axis, Whitesides line, transepicondylar axis) when soft tissue tension was managed intraoperatively using a navigation system. The mean angles for the transepicondylar line, Whitesides line, and the posterior condylar line from the proximal tibia resection plane were 1.29 degrees +/- 3.67 degrees (mean +/- SD; range, -7 degrees to 10.5 degrees), 3.90 degrees +/- 4.17 degrees (mean +/- SD; range, -3 degrees to 15.5 degrees), and -4.03 degrees +/- 2.71 degrees (mean +/- SD; range, -9.5 degrees to 1.0 degrees), respectively. The coefficients of variation (SD/mean x100) for these 3 variables were 283%, 106%, and 67%, respectively. Of the 3 reference axes used widely for femoral component rotation, the angles from the posterior condylar line to the proximal tibia resection plane showed the smallest range of variance.

Joint Line Changes After Navigation-assisted Mobile-bearing TKA

The purpose of this study was to analyze the clinical results of patients who underwent navigation-assisted cruciate ligament retention-type mobile-bearing total knee arthroplasty (TKA) according to joint line changes. From September 2004 to January 2006, cruciate ligament retention-type mobile-bearing TKAs were performed using a navigation system (OrthoPilot; B. Braun Aesculap, Tuttlingen, Germany) on 50 knees in 45 patients (2 men, 43 women). The mean follow-up period was 46 (range, 39-55 months), and patient mean age was 65 years. There was 1 case of rheumatic arthritis; all others were of degenerative arthritis. Proximal tibia resection was performed at the sclerotic level of the medial tibial plateau. The distance from the lowest point of lateral tibial plateau (registered point) to the proximal resection plane was measured. Clinical outcomes (range of motion, Knee Society Score) were compared for joint line elevations of > or =3 mm (20 cases) and <3 mm (30 cases). Mean joint line elevation was 1.93 mm (range, -1-5 mm). Joint line change was not found to be associated with difference of clinical results (P>.05). The findings of this study suggest that joint line changes in the range of -1 to 5 mm after cruciate ligament retention-type mobile-bearing TKA do not affect clinical outcome.

Synchronisation of tibial rotational alignment with femoral component in total knee arthroplasty

The rotational axis of the tibial component in total knee arthroplasty described by Insall is generally accepted, but rotational mismatch between the femoral and the tibial components can occur because the alignment of each component is determined separately. We developed a connecting instrument to synchronise the axis of the tibia to the axis of the femur. We compared the rotational axis of the tibial component using our method and medial one third of tibial tuberosity (Insall’s reference) in 70 consecutive TKAs. The rotational axis of the tibial component from the femoro-tibial synchronisation was rotated internally 13.8° ± 5.8° (range, 2° – 24°) more than the axis of Insall’s reference. Eighty three percent of patellae tracked centrally and the patellae tilt measured 2.2° on average. More attention should be given to the rotational congruency between the femoro-tibial components, because the recent prosthetic design has more conforming articular surfaces.RésuméLa rotation axiale du composant tibial dans la prothèse totale du genou décrite par Insall est généralement acceptée mais elle peut poser problème lorsqu’il existe un trouble de rotation sur le composant fémoral et le composant tibial du fait d’une détermination séparée de la position de chaque composant au moment de l’implantation. Nous avons pour cela développé un instrument qui permet de synchroniser l’axe du tibia et l’axe du fémur. Nous avons comparé la rotation axiale du composant tibial en utilisant notre méthode à propos de 70 prothèses totales consécutives du genou. L’axe de rotation après synchronisation des deux composants a été noté en rotation interne. Cette rotation interne est plus importante que celle prévue par l’axe de référence d’Insall qui est représenté par le tiers interne de la tubérosité tibio-intérieure. 83% des rotules avaient une course normale et un accrochage rotulien a été noté dans 2,2% en moyenne. Une attention particulière doit être portée à la congruence en rotation des éléments fémoro-tibiaux pendant l’implantation d’une PTG d’autant que cette congruence est plus importante dans les nouveaux dessins de prothèses totales du genou récentes.

Modular Cementless Total Hip Arthroplasty for Multiple Epiphyseal Dysplasia

We analyzed a consecutive series of 23 total hip arthroplasties that had been performed using modular cementless prostheses in 13 patients with a confirmed diagnosis of multiple epiphyseal dysplasia and end-stage osteoarthritis of the hip. The average Harris hip score improved from 40.6 to 93.8 points. Postoperatively, all hips demonstrated favorable alterations in the biomechanical parameters including hip center of rotation, femoral offset, femoral neck length, and limb length. At a mean follow-up of 4.8 years, no hip required revision because of aseptic loosening of the acetabular or femoral component. One patient (1 hip, 4.3%) underwent reoperation for polyethylene wear and osteolysis 8 years after index arthroplasty. This study shows encouraging clinical and radiographic outcomes of modular cementless total hip arthroplasties for this technically difficult condition.

Soft Tissue Balancing of Varus Arthritic Knee in Minimally Invasive Surgery Total Knee Arthroplasty: Comparison between Posterior Oblique Ligament Release and Superficial MCL Release

Purpose To assess proper soft tissue balancing of the varus arthritic knee between posterior oblique ligament (POL) release group and superficial medial collateral ligament (SMCL) release group. Materials and Methods This retrospective study was performed on 186 patients who underwent minimally invasive surgery (MIS) total knee arthroplasty (TKA) from January 2011 to December 2011. Eighty-three patients were in the group of SMCL release and 103 patients were in the POL release group. We intended to use a 10 mm polyethylene insert (PE) during TKA, and retrospectively compared the actual thickness of PE between POL release group and SMCL release group. Results The mean PE thickness was 10.59±1.3 mm (range, 8 to 15 mm) in POL group and 11.88±1.8 mm (range, 10 to 18 mm) in SMCL group (p=0.001). We found a significant difference in the mean PE thickness between POL release group and SMCL release group. Conclusions POL and deep MCL releases in MIS-TKA would be beneficial for varus deformity correction in the osteoarthritic knee.

A case-control study of spontaneous patellar fractures following primary total knee replacement

Peri-prosthetic patellar fracture following resurfacing as part of total knee replacement (TKR) is an infrequent yet challenging complication. This case-control study was performed to identify clinical, radiological and surgical factors that increase the risk of developing a spontaneous patellar fracture after TKR. Patellar fractures were identified in 74 patients (88 knees) from a series of 7866 consecutive TKRs conducted between 1998 and 2009. After excluding those with a previous history of extensor mechanism realignment or a clear traumatic event, a metal-backed patella, any uncemented component or subsequent infection, the remaining 64 fractures were compared with a matched group of TKRs with an excellent outcome defined by the Knee Society score. The mean age of patients with a fracture was 70 years (51 to 81) at the time of TKR. Patellar fractures were detected at a mean of 13.4 months (2 to 84) after surgery. The incidence of patellar fracture was found to be strongly associated with the number of previous knee operations, greater pre-operative mechanical malalignment, smaller post-operative patellar tendon length, thinner post-resection patellar thickness, and a lower post-operative Insall-Salvati ratio. An understanding of the risk factors associated with spontaneous patellar fracture following TKR provides a valuable insight into prevention of this challenging complication.

Comparison of cruciate retaining and PCL sacrificing TKA with respect to medial and lateral gap differences in varus knees after medial release.

We aimed to clarify whether the increase in medial gap after medial release is influenced by the retention or sacrifice of posterior cruciate ligament (PCL) during navigation-assisted total knee arthroplasty. After matched pairs were done according to the equality of preoperative varus deformity and medial collateral laxity, 54 knees of each type were available for this study. In the PCL sacrificing group, the mediolateral gap difference significantly increased in both flexion and extension as the preoperative mechanical axis angle increased whereas in the cruciate retaining group, the mediolateral gap difference did not show this tendency. When preoperative mechanical axis angles were over 10.4° in extension and over 7.7° in flexion, the medial gap showed greater increases in PCL sacrificing groups than in cruciate retaining groups.

Primary Total Knee Arthroplasty in Infection Sequelae About the Native Knee

The aim of this study is to assess the results of primary total knee arthroplasty (TKA) after bone or joint sepsis about the native knee and to analyze the risk factors of periprosthetic infection. Sixty-two patients (62 knees), considered to have prior sepsis history to be resolved, underwent primary TKA and were followed during a mean of 6.1years (range, 2-10.4years). Of the 62 patients, periprosthetic infection occurred in 6 after primary TKA (9.7%). Five of 6 patients grew the same organism as prior infection. The number of prior surgeries undertaken for deep infection was found to be an independent risk factor of periprosthetic infection.

How to Minimize Rotational Conflict between Femoral & Tibial Component in Total Knee Arthroplasty: The Use of Femoro-Tibial Axial Synchronizer (Linker)

Purpose The purpose of this study was to investigate the correlation between rotational axes of femur and tibia with the use of Linker. Materials and Methods This study was carried out from August 2009 to February 2010 on 54 patients (106 knees), who were diagnosed with simultaneous bilateral total knee arthroplasty. With the use of postoperative computed tomography scans, it was investigated how much the rotational angle of femoral and tibial components matched. Results The tibial component was internally rotated for the femoral component at an angle of 0.8°. The femoral component was externally rotated for the surgical transepicondylar axis (TEA) at an angle of 1.6 (range: from 4.8° of internal rotation to 7.9° of external rotation, SD=2.2°), and the tibial component was externally rotated for the surgical TEA at an average angle of 0.9 (range: from 5.1° of internal rotation to 8.3° of external rotation, SD=3.1°). Conclusion The femoro-tibial synchronizer helped to improve the orientation and positioning of both femoral component and tibial component, and also increase the correlation of the rotational axes of the two components.