[Precise, computed-assisted leg angle correction with open-wedge high tibial osteotomy]. / Präzise computergestützte Beinachsenkorrektur mit öffnender valgisierender Tibiakopfosteotomie.

AIM: This prospective study investigates open-wedge high tibial osteotomy performed with the aid of a kinematic computer-guided navigation system. After the X-ray control the osteotomy was stabilized by internal LCP fixation. The aim of the study was to demonstrate the accuracy of the navigation system and to prove the reliability of the LCP fixation. METHOD: A total of 39 patients were operated between 2002 and 2003 following this method. The outcomes were evaluated at least 2 years after the surgery clinically and radiologically; 21 females (1 female underwent bilateral osteotomy) and 18 males were included in the study sample. RESULTS: Prior to the osteotomy, the mean anatomic lateral tibiofemoral angle (aLTFA) was 181.1 degrees . The desired 4 degrees "overcorrection" of valgus (aLTFA 170 degrees) was found on X-rays postoperatively in all cases. The mean correction was 11.1 degrees. The correction achieved was stable during the 2-year follow-up period. The osteotomy healed in all cases after 4 months. The full range of motion remained after the surgery in all cases. All patients were satisfied with their results. The Lysholm score was 55 points before and 82 points after the osteotomy (27 points difference). CONCLUSION: The computer-assisted open-wedge high tibial osteotomy with tricortical grafts stabilized by LCP fixation gives exact and reproducible results without loss of correction.

[Defect of the femoral condyle in the knee after patellectomy. Long-term results of fresh massive osteochondral allografting]. / Femurkondylendefekt im Knie nach Patellektomie. Langzeitergebnis einer frischen massiven osteochondralen Allotransplantation.

The presence of a massive full-thickness osteochondral defect in the knee of young and active individuals is an unsolved problem in orthopedic surgery, especially in post-traumatic large bone defects. Fresh massive osteochondral allografts have been used for many years but mostly in oncology but not in post-traumatic cases. This case report describes a 20-year-old right leg-dominant woman, who, at age 19, sustained open Gustilo-Anderson type III comminuted fractures of the left patella and lateral femoral condyle in a motorbike accident. Initial treatment included immediate débridement and patellectomy with lavage. The large defect of the femoral condyle was reconstructed with a massive osteochondral allograft 1 year after the injury. The graft was obtained from our institutional tissue bank. The damaged bearing part of the condyle was resected to bleeding bone to create the nearly rectangular defect. The central condyle wall remained intact. The graft was trimmed to fit the defect and fixed with three cancellous 6.5-mm screws. The meniscus was not damaged. Partial weight bearing was permitted at 8 weeks and full weight bearing at 16 weeks after the surgery. At the last follow-up control 10 years after the surgery, no evidence of tibiofemoral arthrosis was present. The allograft-host interface was not visible. The radiodensity of the graft was nearly identical to the host bone. The Lysholm score and clinical findings were identical (100 points) to those 18 months after the surgery. The patient was extremely satisfied without complaints at 30 years of age.

[Our experience with an image guided navigation system for accurate alignment in total hip replacement by minimally invasive posterolateral surgery]. / Zkusenosti s navigací jamky TEP kycelního kloubu pri posterolaterálním miniinvazivním prístupu.

PURPOSE OF THE STUDY: The aim of the study was to compare a radiographic position of the acetabular component with a position guided by the navigation system in final acetabular cup alignment. MATERIAL: Between May and October 2005, 15 patients underwent implantation of a cementless acetabular component from the posterolateral minimally invasive approach with the use of kinematic navigation. METHODS: The final acetabular cup alignment was determined from the data saved in the navigation system. The radiographic measurement of acetabular cup inclination was made from an anteroposterior projection of both hips on one image, and anteversion was determined by the Ackland method. RESULTS: The average values for inclination and anteversion shown on radiographs were 41.8 degrees (range, 35-51) and 19.8 degrees (range, 5-32), respectively. The average values of cup alignment recorded at implantation by the navigation system were 27.6 degrees (range, 22-35) for inclination and 24.3 degrees (range, 17-28) for anteversion. DISCUSSION: The acetabular cup alignment is considered optimal when inclination is 45 degrees and anteversion 15 degrees. This is more difficult to achieve in minimally invasive surgery due to a limited view of the operating field. This disadvantage can be overcome by using various navigation systems the function of which depends on the accuracy of recorded data. CONCLUSIONS: Because the data recorded by the system used in our study were not accurate, we do not consider the OrthoPilot navigation system to be an effective aid in minimally invasive posterolateral surgery.

[Minimally invasive and navigated implantation for total knee arthroplasty: X-ray analysis and early clinical results]. / Minimal-invasive und navigierte implantation von knietotalendoprothesen: radiologische analyse und frühe klinische ergebnisse.

Total knee arthroplasty (TKA) alignment is one of the most important factors in long-term prosthesis survival. Minimally invasive surgical (MIS) procedures are becoming more common. There may be an increased overall complication rate, especially component malpositioning, due to poor visualisation. The disadvantage of restricted visualisation in the less invasive technique can be compensated by a navigation system. This combined procedure is described in this paper. A total of 40 Search Evolution TKAs were implanted using OrthoPilot navigation in the standard manner, and 40 TKAs were implanted using MIS via a subvastus approach. Primary osteoarthritis of the third or fourth degree, without severe valgus deformity, was the indication. These patients were then selected at random as they came to the institution. The results were evaluated radiologically and clinically.Pain, range of motion, gait and function, and the entire clinical score 10 days after the operation were significantly better in the MIS-group. At 6 and 12 weeks postoperatively, these results were no longer statistically significant. Ideal radiological results were obtained in all cases. No differences in limb axis and component alignment were found after the operation between the navigated groups. MIS is technically very demanding. That is why it should be used only in carefully selected cases. Its advantages occur in the first weeks after the surgery. The long-term results must still be determined.

[Correlation of long-term clinical and radiological results after meniscectomies]. / Korelace dlouhodobých klinických a radiologických výsledku po meniskektomiích.

PURPOSE OF THE STUDY: Although surgical treatment of meniscus injuries has made great progress, meniscectomy remains the most frequently indicated intervention. The aim of this retrospective study was to evaluate the long-term radiological results of isolated subtotal and total meniscectomies and compare them with the clinical results. MATERIAL: The assessed group included 22 men and 8 women at an average age of 35 years; nine and 21 knees, respectively, were treated by isolated subtotal and total meniscectomy in the period from 1987 to 1989. The lateral meniscus was operated on in six knees and the medial meniscus in 24 knees. Patients with other injuries to the knee joint or with a systemic disease were not evaluated. The average follow-up was 16 years. The results were compared with the other, non-treated knee. METHODS: The results were assessed by means of the Lysholm scoring system which takes into account limping, support requirement, walking distances, instability, edema, stair ascent and descent, ability to squat and pain. Radiographic osteoarthritis of the knee was classified by the Kellgren and Lawrence system. A grade greater or equal to 2 was taken for a clear sign of arthritis. In addition, the anatomical axis of the lower extremity was evaluated. Anteroposterior projection of both knees under load was made in a standing position on long films and lateral projection was obtained separately on short films. RESULTS: The average Lysholm scores were 87 points (range, 41-100) and 91 points (range, 67-100) in the treated and non-treated knees, respectively. The outcome of meniscectomy was excellent in 14 (47 %), good in eight (27 %), satisfactory in five (16 %) and poor in three (10 %) knees. In 12 patients (40 %) the state of the treated knee was evaluated as being equal to that of the non-treated knee and in eight patients (27 %) it was even better. Osteoarthritis of the affected compartment was found in eight treated knees and that of the corresponding compartment on the opposite side in four knees. Grade 2 Kellgren- Lawrence radiographic changes were present in four, grade 3 in two and grade 4 in two knees treated by meniscectomy. The anatomic femoro-tibial angle differed between the treated and non-treated side, by 4 degrees on average (range, 2 degrees to 10 degrees ), in 13 (43 %) patients. DISCUSSION: Johnson et al. found at follow-up for about 17 years that osteoarthritis developed more often in the treated than in healthy contralateral knees (40 % as against 6 %). Tapper and Hoover reported that 45 % of men and 10 % of women were without subjective complaints at 10 to 30 years of follow up. In the relevant Czech literature, only Pasa et al. have recently paid attention to the development of lesions in knees treated by meniscectomy, but they have largely evaluated changes occurring after partial arthroscopic meniscectomies. CONCLUSIONS: The present study showed that osteoarthritis after subtotal or total meniscectomy developed in 27 % of the patients at an average follow-up of 16 years. In less than half of the patients, a deviation of the anatomical axis occurred in the treated lower extremity, as compared with the other healthy side. Lysholm scores worse in the treated than the non-treated knee were found in one third of the patients.However, a deviated knee joint axis and/or osteoarthritic lesions did not always correlate with deteriorated clinical findings.

Radiological study of tha after mini-incision technique.

Mini-incision procedures reduce perioperative blood loss, postoperative pain, time of the postoperative recovery, length of the surgical scar, and hospitalisation time. Implant malposition and poor stability are potential risks for compromising long-term results. Between September 2000 and February 2002 (18 months), 120 cemented primary total hip arthroplasties for primary osteoarthritis were performed at the authors institutions. In 60 of these cases selected at random, a posterolateral mini-incision up to 10 cm was used. Sixty other THAs were implanted through a standard posterolateral approach. The radiological measurements of the inclination and anteversion of the cup and stem position were performed and statistically evaluated by use of Mann-Whitney U and Bartlett tests. In the mini-incision group the average inclination angle was 42.3 (range 36 to 52) and the anteversion angle 13.6 (range 6 to 21). The femoral component coronal alignment was within 3 of neutral position in 54 cases (90.0 %). In the standard implanted group the average cup inclination angle was 42.4 (range 35 to 50) and anteversion angle 13.6 (range 8 to 24). Fifty-three stems (88,3 %) were implanted correctly. Statistical analysis found no significant difference in component position between the two groups. There are therefore no potential risks of compromising long-term results after the mini-incision procedure. The authors are encouraged to continue this technique. (Hip International 2005; 15: 98-101).

[Implantation of a non-cemented acetabulum with the use of a navigation system]. / Implantace necementované jamky s vyuzitím navigacního systému.

PURPOSE OF THE STUDY: To compare, on the basis of clinical and radiographic findings, the results of non-cemented acetabulum implantation involving the use of a CT-free navigation system with those of implantation without its use. MATERIAL: A total of 50 patients undergoing implantation of a non-cemented acetabulum in the period from April 2002 to September 2003 were evaluated. Twenty-five patients operated on without the navigation system were included in group 1 on a random basis and 25 patients treated with the use of the system constituted group 2. METHODS: Both groups were evaluated on the basis of clinical and X-ray findings. The radiographic measurement of acetabulular inclination was based on anteroposterior projection of both hips made on films on films equal in size. Anteversion of the acetabulum was assessed according to the Ackland system. The Merle d'Aubigne and Postel scores were used for clinical evaluation. The results were compared statistically. RESULTS: In group 1, the average inclination was 50.6 degrees (range, 38-62) and the average anteversion was 9.4 degrees (range, 3-18). In group 2, the values were 43.0 degrees (32-55) and 10.4 degrees (8-16) for the average inclination and anteversion, respectively. The difference in acetabular inclination between the two groups was statistically significant. When accuracy was evaluated, the difference in acetabular anteversion was statistically significant. DISCUSSION: The achievement of an optimal position of the acetabular component is one of the important factors for good, long-term outcomes of hip replacement. The optimal position that, as suggested by many authors, involves an inclination of 45 +/- 10 degrees and an anteversion of 15 +/- 10 degrees provides sufficient stability, low wear and a satisfactory range of motion in the hip joint. The results close to these values were achieved in the patients included in group 2. CONCLUSIONS: A comparison of the groups showed that the computer-assisted navigation system used in implantation resulted in an optimal position of the acetabular component.