The effect of femoral notching during total knee arthroplasty on the prevalence of postoperative femoral fractures and on clinical outcome

BACKGROUND: The treatment of a supracondylar femoral fracture following total knee arthroplasty is complicated by the presence of the prosthetic components. Anterior femoral notching during arthroplasty has been implicated as a contributing risk factor for femoral fracture. We retrospectively reviewed the effect of anterior femoral notching on the subsequent occurrence of a periprosthetic supracondylar fracture of the distal aspect of the femur and the outcomes of primary total knee arthroplasty in such patients. METHODS: The prevalence and depth of femoral notching were determined on a review of the lateral radiographs by observers blinded to the clinical results of 1089 consecutive total knee replacements performed in 1997 and 1998. Linear and logistic regression modeling was used to analyze the relationship between femoral notching and the prevalence of supracondylar femoral fracture, postoperative range of motion, the Knee Society score, and the Knee Society functional and pain scores. RESULTS: Femoral notching was performed in 325 (29.8%) of the 1089 knees in our series. During an average follow-up period of 5.1 years, only two supracondylar femoral fractures occurred, both in femora treated without notching. Femoral notching was not associated with an increased rate of fracture (p = 1.000) or with significant differences in the measures of outcome (range of motion [p = 0.117], knee score [p = 0.967], functional score [p = 0.861], need for a lateral release [p = 0.234], or postoperative pain [p = 0.948]). CONCLUSIONS: This study demonstrated no difference in knees managed with or without notching of the anterior distal aspect of the femur with respect to the occurrence of a supracondylar fracture, range of motion, Knee Society score, Knee Society function, or pain.     

Risk of periprosthetic fracture after anterior femoral notching: A 9-year follow-up of 200 total knee arthroplasties

Background Notching of the anterior femoral cortex in distal femoral fractures following TKR has been observed clinically and studied biomechanically. It has been hypothesized that femoral notching weakens the cortex of the femur, which can predispose to femoral fractures in the early postoperative period. We examined the relationship between notching of the anterior femoral cortex during total knee replacement (TKR) and supracondylar fracture.Patients and methods Postoperative lateral radiographs of 200 TKRs were reviewed at an average of 9 (6–15) years postoperatively. 72 knees (41%) showed notching of the anterior femoral cortex. Notches were classified into 4 grades using the Tayside classification as follows. Grade I: violation of the outer table of the anterior femoral cortex; grade II: violation of the outer and the inner table of the anterior femoral cortex; grade III: violation up to 25% of the medullary canal (from the inner table to the center of the medullary canal); grade IV: violation up to 50% of the medullary canal (from the inner table to the center of the medullary canal) and unclassifiable.Results The interobserver variability of the classification system using Cohen''s Kappa score was found to be substantially reliable. 3 of the 200 TKRs sustained later supracondylar fractures. One of these patients had grade II femoral notching and the other 2 showed no notching. The patient with femoral notching sustained a supracondylar fracture of the femur following a simple fall at home 9 years after TKR.Interpretation There is no relationship between minimal anterior femoral notching and supracondylar fracture of the femur in TKR.     

Does Femoral Notching During Total Knee Arthroplasty Influence Periprosthetic Fracture. A Prospective Study

BackgroundNotching of the anterior femoral cortex during total knee arthroplasty (TKA) has been attributed to cause supracondylar fractures of the femur. Anatomic variations in the femur bone in different races make notching inevitable when standard designs of prostheses are used. The objective of this study is to determine the prevalence of notching when a PFC Sigma knee was used in an Indian population sample using the anterior referencing system and to assess the frequency of femoral shaft fractures in these cases.MethodsThis is a single-center, prospective study. All patients undergoing TKA were recruited and followed up for a minimum of 2 years. All patients had a PFC Sigma knee (DePuy Synthes), and the anterior referencing system was used for implantation. The Knee Society Score was used for outcome scoring and the Gujarathi’s schema for the grading of notching. Radiological outcomes were evaluated by an independent observer. Linear regression analysis assessed the effect of notching on range of motion and final score.ResultsOf the 200 cases, 21% had varying degrees of notching. Grade I was seen in 13%, grade II in 6.5%, grade III in 1%, and grade IV in 0.5% in this series. There was no supracondylar fracture in 2 years. Notching had no bearing on the range of movement or outcome scores.ConclusionAlthough notching is best avoided, this study has shown no correlation between notching and supracondylar fracture of the femur following TKA. It does not appear to have any bearing on the range of movement or final outcome scores.     

The consequences of anterior femoral notching in total knee arthroplasty. A biomechanical study

BACKGROUND: Notching of the anterior femoral cortex during total knee arthroplasty has been implicated as a cause of subsequent periprosthetic supracondylar femoral fracture. However, other than observational clinical data, no reliable association between these events has been established, to our knowledge. The purpose of the present study was to investigate the biomechanical effects of notching of the anterior femoral cortex. METHODS: The femoral component of a total knee replacement was implanted in twelve matched pairs of human cadaveric femora; one specimen in each pair had preservation of the anterior femoral cortex, and the other had a full-thickness cortical defect created just proximal to the anterior flange of the femoral component. The pairs were then subjected to either bending or torsional loading to failure. Both the fracture pattern and the quantitative load to failure were analyzed. Two matched pairs were excluded from the analysis because of inadvertent fracture during placement of the component. RESULTS: Following the application of a bending load, femora with notching of the anterior femoral cortex sustained a short oblique fracture that originated at the cortical defect proximal to the femoral component and femora without notching had a midshaft fracture. In contrast, notching of the anterior femoral cortex had no effect on the fracture pattern that was observed after the application of a torsional load. The mean load to failure was significantly reduced by notching in both testing modes. Notching decreased bending strength from 11,813 to 9690 newtons (18 percent; p = 0.0034), and it decreased torsional strength from 134.7 to 81.8 newton-meters (39.2 percent; p = 0.01). CONCLUSIONS: Biomechanical testing demonstrated that notching of the anterior femoral cortex significantly lessens the load to failure following total knee arthroplasty and influences the subsequent fracture pattern. These effects are manifested in different ways under the two loading conditions: the fracture pattern is altered under bending load, and there is a greater quantitative decrease in load to failure with torsional loading. CLINICAL RELEVANCE: Weakening of the femur by notching of the anterior cortex after total knee arthroplasty may warrant alteration in the customary postoperative regimen for these patients. Manipulation of a total knee replacement with a notched anterior femoral cortex should probably be avoided.     

A custom-made prosthesis for the treatment of supracondylar femoral fractures after total knee arthroplasty: report of four cases

Four supracondylar femoral fractures following total knee arthroplasty, two because of intraoperative notching of the anterior femoral cortex and two because of osteoporosis, were revised using a custom-made prosthesis with femoral condyle section. At 1-6 year follow-up (median 3 years) after the revision, all patients had an excellent clinical result, although 2 had a prolonged rehabilitation period because of severe osteoporosis. At roentgenographic examination, no signs of loosening of the prostheses at the cement-bone interface were present.     

Infection after an open supracondylar fracture above a total knee arthroplasty treated with the supracondylar nail

A 72-year-old man with an open fracture above a total knee arthroplasty was treated with a supracondylar intramedullary nail. Five months after internal fixation, the patient developed a Staphylococcus aureus infection of the knee, which resolved after a 42-day course of IV antibiotics. After reimplantation with a posteriorly stabilized condylar total knee arthroplasty using femoral and tibial stems with vancomycin-impregnated cement, the patient has been pain-free and ambulatory at 8 months' follow-up. The supracondylar nail may be an acceptable internal fixation device for closed fractures above a total knee arthroplasty, but, if possible, open fractures in this location may be better treated with fixation devices that do not violate the knee joint.     

Supracondylar fracture of the femur after total knee arthroplasty

We reviewed the data on thirty-six supracondylar fractures of the femur (in thirty-four patients) that occurred after total knee arthroplasties that were done between April 1974 and December 1981. Patients who had osteoporosis, rheumatoid arthritis, one or more previous arthroplasties of the knee, or inadvertent breeching of the anterior aspect of the femoral cortex at operation appeared to be particularly at risk for a supracondylar femoral fracture. Malalignment of the component could not be implicated as a cause. Twenty-six fractures (in twenty-five patients) were treated by non-operative methods. Seventeen of them (65.4 per cent) healed and required no surgical treatment. Fourteen of the seventeen were followed for more than two years; they had no significant difference in the knee score and lost less than 10 degrees of motion. The nine remaining knees required revision of the arthroplasty because of non-union in four knees, malunion in two, loosening of the component in two, and extension lag in one. At an average of forty months after revision, the nine knees were rated as having one excellent, four good, three satisfactory, and one failed result. In contrast, only three of the five fractures that were treated by early open reduction and internal fixation had a satisfactory result, and one of them required a second bone-grafting procedure. One patient died perioperatively and another required an above-the-knee amputation because of sepsis. Of the three fractures that were initially treated by external fixation, one had an excellent and two had a good result at an average of forty-five months after fracture. We have found that supracondylar fractures that occur after total knee arthroplasty can be managed by either traction or application of a cast, or both, which usually results in healing of the fracture and a satisfactory outcome of the arthroplasty. Patients who have a poor arthroplasty result after non-operative treatment of the fracture usually can undergo a revision arthroplasty with the expectation of a satisfactory outcome. Operative treatment of the fracture should be reserved for patients who do not have osteopenia and in whom stable fixation can be achieved, for those who demand a highly functional arthroplasty, and for those in whom adequate closed reduction cannot be maintained.     

Anterior femoral notching and ipsilateral supracondylar femur fracture in total knee arthroplasty

The authors reviewed 670 total knee arthroplasties with a 2-10-year follow-up period. Of these, 180 knees had anterior femoral notching, which was deeper than 3 mm in 138. Two of the 670 knees suffered ipsilateral supracondylar fractures; one of these had a notched femur and one did not. Both fractures occurred at the anterior patellar flange-bone junction. No correlation was found between anterior femoral notching and ipsilateral supracondylar femur fracture.     

全膝关节置换术后KimⅠB型股骨侧假体周围骨折的手术治疗

目的探讨膝关节表面置换术后股骨假体周围骨折的手术方法及临床疗效。方法回顾性分析2015年7月至2019年7月采用手术治疗的9例股骨假体周围骨折患者,女性8例,男性1例,年龄65～92岁,平均(75.3±8.7)岁。所有病例均为初次膝关节表面置换术后,假体为骨水泥型。Kim分型均为ⅠB型。骨折发生时间为术后3个月至14年,平均(6.1±3.9)年。依据骨折特点,采用钢板或髓内钉内固定。随访时记录膝关节活动度、关节功能及骨折部位疼痛视觉模拟评分(visual analogue scale,VAS),通过骨折部位的疼痛情况及X线片来判断骨折是否愈合。结果所有病例均获得随访,时间为12～36个月,平均(28±8.5)个月。8例患者骨折部位负重VAS评分为0分,达到临床愈合; 1例术后骨折未愈合。骨折临床愈合率88.9%(8/9)。末次随访时HSS评分20～90分,平均(74.0±19.6)分;除1例骨折不愈合外,无其它并发症。结论针对不同股骨假体周围骨折的特点,制定相应的手术方案,结合早期功能锻炼,可取得较好的临床效果。     

Outcome of periprosthetic distal femoral fractures following knee arthroplasty

IntroductionThe majority of periprosthetic fractures around the knee occur at the supracondylar region of the distal femur. Fixation of distal femoral fractures in osteoporotic bone with short segment remains a challenge, especially after total knee arthroplasty (TKA). Internal fixation of these fractures using locking plates has become popular. The purpose of this study was to evaluate a consecutive series of periprosthetic supracondylar femoral fractures treated with locked periarticular plate fixation with regard to surgical procedure, complications and clinical outcome.Materials and methodsFrom two academic trauma centres, 55 consecutive periprosthetic distal femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association, AO/OTA 33) were retrospectively identified as having been treated with locked plate fixation. Of these, 36 fractures in 35 patients (86.1% female) met the inclusion criteria. Patients had an average age of 73.2 years (range 54–95 years). Fixation constructs for plate length and working length were delineated. Nonunion, infection and implant failure were used as complication variables. Demographics were assessed. Outcome was addressed radiographically and clinically according to Kristensen et al.¹ by range of motion and pain.ResultsTwenty-five of 36 fractures (69.4%) healed after the index procedure. Eight of 36 fractures (22.2%) developed a nonunion with three fractures (8.3%) leading to hardware failure. Nine of the 36 patients (25%) were radiographically diagnosed with notching of the anterior femoral cortex. Regarding technical aspects, distance from the anterior flange of the femoral component to fracture was significantly shorter in patients with compared to without anterior notching (t = 3.68, p = 0.02). Patients who underwent submuscular plate insertion compared to an extensive lateral approach had a reduced nonunion risk (χ² = 0.05). No difference in infection rate was found for submuscular procedures compared with open procedures (χ² = 0.85). Range of motion was reduced in most of the patients and 13.5% had a persistent loss of extension of 5°. More than 77% of the patients reported no or only mild pain during the last office visit. Range of motion loss did not influence pain. Successful treatment according to Cain et al.² was achieved in 83%. Using Kristensen's¹ criteria, 56% of the knees had acceptable flexion.ConclusionOperative fixation of periprosthetic distal femoral fractures after TKA continues to be challenging. Notching of the anterior femoral cortex should be avoided. Loss of reduction and high failure rates still occur with locked plating and may be related to underlying factors. Indirect reduction and submuscular plate insertion technique reduce nonunion risk.     

Ender nailing for supracondylar fracture of the femur after total knee arthroplasty: five case reports

We studied 5 women with supracondylar fractures after total knee arthroplasty (TKA). The mean age at fracture was 67.4 years. Four patients had chronic rheumatoid arthritis, and 1 had osteoarthritis. The range of motion, knee score, femorotibial angle, and component alignment were investigated. Flexion was slightly decreased after Ender nailing, but extension only changed in 1 patient. The knee score decreased, but all patients were ambulatory. The femorotibial angle changed in all patients. Measurement of femoral component alignment showed a postoperative change of angle alpha (1 degrees to 11 degrees ) and angle gamma (0 degrees to 9 degrees ). Union was achieved in all patients. Ender nailing is an acceptable method of treatment for supracondylar fractures of the femur after TKA if the nails can be inserted deeply into the femoral condyles.     

Cemented internal fixation for supracondylar femur fractures in osteoporotic patients

Seventeen, supracondylar femur fractures in 15 severely osteoporotic patients (average age, 81.9 years) were treated with a 95 degree supracondylar plate and dynamic compression screw supplemented with intramedullary methyl methacrylate and massive cancellous bone graft harvested from the distal femoral metaphysis. Interfragmentary compression and rigid fracture fixation was obtained in all cases with the use of the A-O compression device. Patients were allowed early protected weight bearing without external immobilization. At follow-up observation (average, 2.1 years), bony union was noted in all cases, and knee flexion averaged 100.4 degrees. There were no malunions or cases of implant failure. Complications included two early postoperative deaths and three femur fractures above the plate. This technique was effective in rapidly restoring patient mobility while avoiding the complications of implant failure.     

Supracondylar fracture of the femur after total knee arthroplasty

In a review of 250 total knee arthroplasties, five patients with rheumatoid arthritis incurred supracondylar fractures of the femur. These fractures may be associated with a surgical encroachment of the anterior femoral cortex during resection of the patellar trochlea. Forty-two percent of patients with excessively deep resections of the patellar trochlea suffered fractures. No fractures occurred in patients without encroachment of the anterior femoral cortex. All patients with fractures also had significant osteoporosis, which may have predisposed them to fracture. A resection of the patellar trochlea that is made too deeply would interrupt the transmission of stresses through the cancellous bony trabeculae of the anterior femoral cortex and could predispose to fracture.     

A new method of treatment for periprosthetic supracondylar fractures of the femur for prostheses with a stemmed femoral component

Knee arthroplasty periprosthetic supracondylar fracture of the femur is a well-recognized problem that is likely to be seen more frequently with the increasing number of knee arthroplasties being performed. Treatment of this fracture is difficult. A new method of internal fixation for supracondylar fractures around a stemmed femoral component using a custom-made extension to the femoral stem is described. This technique allowed early mobilization of the patient, with restoration of a good range of movement of the knee and fracture union within 1 year.     

Periprosthetic supracondylar femur fractures following total knee arthroplasty

Periprosthetic supracondylar femur fractures following total knee arthroplasty (TKA) are an infrequent, but devastating, complication. From 1998 to 2000, we treated 30 supracondylar femur fractures above TKAs. Eighteen fractures were managed with retrograde intramedullary rod fixation (FIMR) and the other 12 fractures with traditional open reduction with internal fixation (ORIF). Follow-up averaged 3 years, with Knee Society knee scores being 84 and 82, respectively. Complications included 1 above-knee amputation for deep sepsis and 1 nonunion with varus alignment. FIMR appears to be the treatment of choice when it is feasible. However, traditional ORIF also may yield satisfactory results in those designs that cannot accommodate retrograde FIMR fixation.     

Operative management of periprosthetic femur fractures in the elderly using biological fracture reduction and fixation techniques

Treatment of periprosthetic femur fractures often requires deviation from standard fixation techniques due to the presence of associated arthroplasty components, however, the use of adjuvant bone grafts and bone graft substitutes remain controversial. 59 patients (average age, 74 years) with either a periprosthetic femoral shaft about an arthroplasty stem (n=29) or supracondylar fracture above a total knee arthroplasty (n=30) were treated with biological open-reduction internal-fixation techniques without the use of bone grafts or bone-graft substitutes. All except one patient healed after the index procedure. Three patients had progressive malalignment associated with failed screw fixation but all healed without further surgical intervention. 49 out of the 59 patients returned to their baseline level of function. These results indicate that use of adjuvant bone graft materials may not be routinely necessary when treating periprosthetic femur fractures using lateral plates and biological reduction and fixation techniques.     

Cruciate-retaining stemmed total knee arthroplasty for supracondylar-intercondylar femoral fractures in elderly patients: a report of three cases

The treatment of supracondylar or intercondylar femoral fractures in elderly patients with gonarthrosis is a difficult problem. Primary total knee arthroplasty (TKA) can be considered as a treatment modality for these patients, and several authors have reported acceptable results with this option. They have performed TKA using custom-made, hinged, or constrained components with long stem for fracture reduction and stabilization. But use of hinged or constrained total knee arthroplasties for dealing with supracondylar and intercondylar fractures may be unnecessary, and an alternative is to use a cruciate-retaining stemmed TKA. We report 3 elderly female patients who had supracondylar or intercondylar femoral fractures and coexisting gonarthrosis treated by primary TKA with use of a cruciate-retaining augmentable femoral component with stem extension. All patients improved their ambulatory status and showed good knee function. We believe that use of a cruciate-retaining type of component is a reasonable alternative to the use of a more constrained prosthesis in the treatment for this group of patients.     

An unusual way of intramedullar fixation after a periprosthetic supracondylar femur fracture

Periprosthetic supracondylar femoral fractures after a total knee arthroplasty are difficult surgical problems. We report a case of an 84-year-old woman with an osteoporotic fracture that was not deemed amenable to conventional treatment. In this case, a complete consolidation was achieved by using a proximal femur nail antirotation nail upside down and through the fracture for fixation.     

Bilateral femoral neck stress fractures following total knee arthroplasty: a case report and review of literature

Stress fracture of the femoral neck following total knee arthroplasty (TKA) is an uncommon complication with only 20 cases having been described in English literature so far. Stress fractures of femoral neck occurring simultaneously on both sides following a bilateral total knee replacement is an exceptional occurrence, which to the best of our knowledge, has not been described previously. We describe a patient suffering from osteoarthritis of both knees, who was treated with bilateral total knee arthroplasty simultaneously. He developed spontaneous fractures of femoral neck on both sides 9 months following the total knee replacement in the absence of any known risk factors for stress fractures. He was treated with bipolar hemi replacement arthroplasty for displaced fracture on one side and closed reduction/internal fixation on the undisplaced side. A high index of suspicion is needed to diagnose this unusual complication of total knee arthroplasty before the fracture displaces necessitating a prosthetic replacement.     

Subtrochanteric femur fractures: a comparison of the Zickel nail, 95 degrees blade plate, and interlocking nail.

Seventy-nine nonconsecutive patients with subtrochanteric femur fractures were divided into three groups based on the method of fracture fixation. Group I consisted of 21 patients treated with a Zickel nail, Group II comprised 25 patients treated with a 95 degrees blade plate, and Group III included 33 patients treated with an interlocking nail. All patients in Group I and Group II had open reduction and internal fixation of their fractures. Ninety-four percent of the patients in Group III were treated by closed intramedullary nailing. The average operating times for Groups I, II, and III were 212, 272, and 181 min, respectively, while blood loss averaged 900, 1,500, and 600 ml for each group, respectively. Group I had one infection, ten malunions, and one nonunion. Group II had one infection, six malunions, and two nonunions. Group III had no infections, two malunions, and one nonunion. We conclude that closed interlocking nailing is the treatment of choice for acute nonpathologic subtrochanteric femur fractures in adults. There is decreased blood loss, reduced operating time, and fewer complications than with either the Zickel nail or the 95 degrees blade plate regardless of the fracture pattern or the degree of fracture comminution.