[Intramedullary nailing of peri-prosthetic fractures following total knee joint replacement]. / Intramedulläre Schienung periprothetischer Frakturen nach totalem Kniegelenkersatz.

Based on positive experiences in similar operations of the said method, we report 3 cases of periprosthetic fractures after total knee arthroplasty treated by the principle of intramedullary osteosynthesis. After preoperative X-ray-planning a shorted AO-medullar nail was positioned on the proximal site of the prostheses in combination with autogenous resp. homogeneous bone grafts located in the fracture area. In relation to other procedures the advantages of these compound osteosyntheses are undisturbed periosteal blood supply, correct alignment and consolidation of the fracture, early weight bearing and reliable cement fixation. They legitimate in our opinion the increased effort of partial revision arthroplasty.

[Reconstruction of metadiaphyseal bone defects of the femur with cortical strut allografts in periprosthetic bone loss]. / Metadiaphysäre Femurdefektrekonstruktion mit kortikalen Strut-Allografts bei periprothetischen Knochendefekten.

OBJECTIVE: Biological augmentation and stabilization of high-grade bone defects with structural allografts from donor femur halfs. INDICATIONS: Severe bone defects with aseptic loosening of hip prosthesis, periprosthetic femoral fracture or non-union, possibly even in cases of a healed infection. CONTRAINDICATIONS: Local or systemic infection. SURGICAL TECHNIQUE: The two modeled strut allografts are temporary fixed epiperiostal anterolateral and -medial with wire cerclages, while protecting the vascular supplying linea aspera of the femur. With the thus stabilized femur, the leg can be placed in the four-position in order to prepare the medullary canal of the revision prosthesis. Finally, the uncemented revision prosthesis is hammered in under successive tightening of the wire cerclages. With this "cracking technique", stem is stabilized and the grafts have repositioning, augmentative, and supportive function. POSTOPERATIVE MANAGEMENT: Partial weight-bearing postoperatively for 12 weeks. X-ray control during surgery, 10 days postoperatively, after 6 and 12 weeks and every 1-2 years. RESULTS: In four different studies, 123 patients were stabilized from December 1991 to June 2011 due to an extensive periprosthetic femoral bone defect and/or periprosthetic fracture, refracture, or non-union with strut allografts. After an average follow-up of 3.8 years (range 0.3-11 years), the average Harris Hip Score was 80.8 (range 44-100). During this time, there was 1 refracture, 103 stable stems, 20 fibrous stable stems, 9 patients with low graft resorption, and 122 patients with radiographic healing of the strut allografts based on classification according to Emerson et al. (Clin Orthop Relat Res 285:35-44, 1992).

[Briard's sagittal sliding osteotomy of the lateral condyle in total knee arthoplasty of the severe valgus knee]. / Die sagittale Gleitosteotomie des lateralen Kondylus nach Briard beim Oberflächenersatz des kontrakten Valgusknies.

OBJECTIVE: Distalization of the insertion of the lateral collateral ligament and popliteus tendon by sliding osteotomy of the lateral femur condyle in order to correct a residual contracture in extension in total knee arthroplasty (TKA) of the severe valgus deformity. INDICATIONS: Genuine and other valgus deformity of the knee. CONTRAINDICATIONS: Severe laxity of the medial collateral ligament; common contraindications of joint replacement. SURGICAL TECHNIQUE: Lateral parapatellar approach and stepwise osteotomy of the tubercle of the tibia, subperiostal release of the lateral contracted structures such as iliotibial band (ITB) and lateral collateral ligament (LCL) in flexion. Tibia first technique, verification of a balanced and stable flexion gap parallel to the epicondylar line. Posterior cruciate ligament (PCL) is preserved. Referencing of the distal femoral cut by a spacer filled only in the medial extension gap. Finishing femoral chamfer cuts. If extension gap remains trapezoidal, further release of the residual lateral contracted structures in extension by means of sliding osteotomy of the lateral condyle and subperiostal release of the capsule and the lateral septum intermusculare is required. Termporary fixation of the lateral condyle by K-wires, resection of the bony excess, trial of test components, definite screw fixation. POSTOPERATIVE MANAGEMENT: Comparable to TKA in varus deformities by a medioparapatellar approach. RESULTS: A total of 79 patients (61 women, 18 men, average age 71 years at the time of surgery) with fixed valgus deformities were operated between June 2001 and December 2010 using TKA and sliding osteotomy of the lateral femoral condyle. The preoperative valgus angle under defined valgus and varus stress was 19.5° (8-40), postoperative 4.7° (2-11). Mean medial angle (valgus stress) of the follow-up was 2.1° (0.5-5°), lateral angle (varus stress) 2.3° (0.5-5°). A total of 35 patients were followed-up, at a mean of 73.3 month (24-109 months). The postoperative Knee Society Score was 95 points (56-100 points), while the postoperative Function Score was 90 points (55-100 points) postoperatively. The Oxford Score improved from 22 points (3-43 points) preoperatively to 45 points (21-48 points) postoperatively. One knee had to be revised due to infection, one knee due to non-union of the tibial tubercle. Finally, there were 3 cases with complications associated with the procedure due to the sliding osteotomy of the lateral femoral condyle; all were revised successfully. No conversion to a semi-constrained or constrained knee prosthesis was necessary.

[Revision of failed acetabular cups with extensive structural allografts]. / Die Revision von gelockerten Hüftendoprothesenpfannen mit ausgedehnten strukturellen Allografts.

AIM: Structural allografts are used with encouraging results for revision of failed total hip arthroplasty and in the surgery of bone tumours. The aim of the present study is to describe the clinical and radiological results achieved with structural allografts in revision of a total hip arthroplasty. MATERIAL AND METHODS: 15 patients (12 female and 3 male patients) were revised with an acetabular defect situation of type 3 A or 3 B according to the Paprosky classification. Five fresh-frozen acetabula, nine distal femora and one proximal tibia were used for acetabular reconstruction. The rigid graft fixation was performed with 2 > or = AO screws. In one case a cemented acetabular ring was implanted, four cementless cups and ten cemented polyethylene acetabular components were used. The mean follow-up was 7.9 years (1.6-11.0 years). RESULTS: A stable osseointegration of fifteen transplanted structural allografts was achieved in thirteen cases. Two allografts (one aseptic loosening, one deep infection) failed to osseointegrate. In one case the migration of a cementless cup was registered. Revision surgery of this female patient was performed successfully with a cemented reconstruction ring. The mean Harris hip score at the latest follow-up was 81.4 points (70-99 points). CONCLUSION: For reconstruction of acetabular bone stock and restoration of the bone anatomy structural allografts can be recommended. The use of cementless cups in combination with structural grafts is to be evaluated as critical.

[Acetabular convexity--a specific addition to total endoprosthetic hip replacement]. / Der Pfannennerkeraufbau--eine spezifische Ergänzung des totalendoprothetischen Hüftgelenkersatzes.

Between 1. 1. 1977 and 30. 6. 1988, 1470 total hip prostheses were implanted at the 1st Orthopedic Clinic in Bad Abbach/Regensburg. In 101 cases (82 patients, average age 54.8 years) the acetabular convexity was built up at the same time. This is considered indicated if the acetabulum is too shallow and thus provides insufficient lateral or dorsolateral countersupport. The main area of indication is dysplasia-coxarthrosis and congenital dislocation of the hip, destructive coxitis in chronic polyarthritis or juvenile chronic arthritis, and loosened prostheses. The material used for building up the convexity is a block of corticocancellous bone, which is fixed ventrolaterally to dorsolaterally to the ilium by osteosynthesis. Autologous material was used in 88 cases and homologous material in 13. Sixty-one patients with a total of 77 built-up convexities were followed up. In 92.2% a bony bridge between the corticocancellous block and the rising branch of the ilium was fund. The method described is a valuable addition to replacements in case of extreme hip joint changes and replacement operations. In the authors' opinion it has considerable advantages over supporting shells and similar materials.

Intertrochanteric osteotomy with a short intramedullary locking nail.

In this study the Gamma nail was used for fixation after intertrochanteric osteotomy in osteoarthritis. In 31 patients varus, valgus and complex intertrochanteric osteotomies were stabilized. The patients were allowed full weight bearing 2 weeks postoperatively. After a mean follow-up of 25.6 (13-42) months 29 osteotomies were healed. Two patients were lost to follow-up. No femoral shaft fractures or thigh pain occurred.

[Curved osteotomy technique for intertrochanteric varus surgery--an experimental and computer-assisted surgery]. / Die Rundosteotomietechnik für die intertrochantäre Varisierung--Eine experimentelle und computergestützte Analyse.

PURPOSE: In conventional intertrochanteric varus osteotomy, shortening of the leg and insufficiency of the abductor muscles occur frequently. To avoid these disadvantages, a curved osteotomy is presented. METHOD: 189 intertrochanteric barrel vault and wedge osteotomies were compared. By means of digitized preoperative radiographs the varus osteotomies were planned with a computer program optimising postoperative leg length, bone contact area at the osteotomy site, femoral offset, and abductor muscle length. RESULTS: The average leg shortening was 3.9 mm (range: 0-5 mm) for barrel vault osteotomy and 13.6 mm (range: 8-22.2 mm) for the wedge technique. After correction the mean contact area at the osteotomy sites was 1731.6 mm2 (range: 1087.8-2341.8 mm2) in the barrel vault technique compared with 783.7 mm2 (range: 563.7-1249.6 mm2) in the wedge procedure (p < 0.001, t-test). Adequate femoral offset was achieved in both types of osteotomy. In all curved osteotomies the length of the abductor muscles remained nearly constant in contrast to the wedge procedure. Additional comparative experimental barrel vault osteotomies in 22 human autopsy femora with a high-speed dissecting tool and round jigs revealed a precise application of the preoperative planning. CONCLUSION: The intertrochanteric curved osteotomy provides minimum leg shortening and increased bone contact area. It can prevent an insufficiency of the abductor muscles, because shortening is minimized.

Supportive strut grafts for diaphyseal bone defects in revision hip arthroplasty.

Large femoral cortical strut allografts were used to provide structural support of the femur in 20 patients in whom uncemented, extensively porous-coated, press-fit revision femoral stems were applied. The mean followup was 4.7 years. Radiographic analysis of the patients who had revision surgery revealed that in all 20 patients, the cortical femoral strut allografts showed incorporation. Small areas of graft resorption were observed in only two patients. Seventeen of the uncemented femoral revision stems radiographically showed bone ingrowth. Three of the revision femoral stems were interpreted as being fixed only by fibrous ingrowth after early subsidence after surgery. There were no reoperations. Before surgery, all patients were unable to walk and had severe pain. At followup, all patients were ambulatory and had considerable improvement in pain relief and in their ability to walk. The mean Harris hip score after surgery was 75 (range, 57.5-92). Complications consisted of one peroneal nerve palsy, which resolved; one deep venous thrombosis; one gastrointestinal ulcer; and one case of pneumonia. Supportive cortical strut allografts represent an alternative to the use of circumferential bulk allografts and total femoral replacements in patients with large combined proximal and diaphyseal bone defects.

Periprosthetic fractures with extensive bone loss treated with onlay strut allografts.

We reviewed a consecutive series of 19 patients with comminuted periprosthetic fractures, loosening of the femoral stem (Vancouver type B3) and significant loss of bone stock (Paprosky type III and IV). Sixteen porous-coated long stems and three Exeter stems, all with impaction grafting, were used. Large femoral onlay strut allografts were applied to maintain fracture reduction and improve stability. There was one early re-fracture at the tip of the femoral stem. Eighteen fractures healed without deformity and shortening. At the last follow-up at mean 3.7 (2.0-7.5) years, the mean Harris hip score was 76.4 (57.5-92.0). There was ingrowth of all strut grafts and significant augmentation of periprosthetic bone.