Endoprothetischer Ersatz des radialen Pfeilers nach Trauma

Non-displaced fractures of the radius head are in most cases treated conservatively. Open reduction and anatomical internal fixation of displaced radius head fractures is the method of choice. In comminuted fractures of the radius head (Mason type III and type IV) replacement with a radius head prosthesis achieves joint stability and prevents secondary complications, such as valgus elbow deformity and proximal radial migration. Modern anatomically formed prostheses show promising results in the medium-term view. Typical complications after radius head replacement are limited range of motion in the elbow joint, arthritis of the capitulum and heterotopic ossifications. In cases of capitulum arthritis, capitulum prostheses were developed to resurface the lateral compartment of the elbow joint. Short-term results are encouraging with improvements in pain and range of movement.     

Can Ulnar Variance Be Used to Detect Overstuffing After Radial Head Arthroplasty?

Background

Overstuffing of the radiocapitellar joint during metallic radial head arthroplasty has been reported to cause loss of elbow flexion, capitellar erosion, and early-onset osteoarthritis. Although this is known, there is no agreed-on measurement approach to determine whether overstuffing has occurred.

Questions/purposes

We therefore hypothesized that overlengthening the radial head during radial head arthroplasty changes the ulnar variance in the wrist.

Methods

Seven cadaveric radii were implanted with radial head prostheses of increasing thickness. Each specimen was implanted successively with increasingly thick radial head prostheses measuring 2, 4, and 6 mm thicker than the native radial head, and radiographs were taken after implantation of each prosthesis. The ulnar variance with each prosthesis was measured using the method of perpendiculars.

Results

The ulnar variance of the native and 2-mm (p = 0.04), 4-mm (p = 0.008), and 6-mm (p = 0.008) overly thick radial head prosthesis-implanted states decreased significantly with each incremental increase in prosthetic head thickness.

Conclusions

Implantation of thicker radial head prostheses decreased the ulnar variance. Our results indicate ulnar variance could be used to detect overstuffing of radial head prostheses.

Clinical Relevance

The simplicity and reliability of ulnar variance make it a potentially useful indicator of overlengthening after radial head arthroplasty.     

Silicone rubber arthroplasty of the wrist

The wrist is often referred to as the keystone of the hand. It is often affected in rheumatoid arthritis. Salvage procedures for patients with rheumatoid arthritis involving the wrist include silicone wrist arthroplasty, total joint arthroplasty, and wrist arthrodesis. In 1967, Swanson developed a double-stem, flexible-hinge implant for the radial carpal joint. In 1982, metal titanium bone liners (grommets) were added to help decrease the incidence of fractures. The authors feel that the gold standard is still wrist arthrodesis. However, they would use a flexible wrist arthroplasty in a patient who has bilateral wrist involvement with marked digital deformity and/or proximal interphalangeal stiffness. This is especially true in low-demand patients who have good alignment, good bone stock, and the associated proximal and distal disease. If these criteria are met and meticulous technique used, successful reconstruction of the wrist with a flexible wrist silicone implant can be performed in the patient with rheumatoid arthritis.     

Short- to mid-term results of metallic press-fit radial head arthroplasty in unstable injuries of the elbow

We assessed the short- to mid-term survival of metallic press-fit radial head prostheses in patients with radial head fractures and acute traumatic instability of the elbow. The medical records of 42 patients (16 males, 26 females) with a mean age of 56 years (23 to 85) with acute unstable elbow injuries, including a fracture of the radial head requiring metallic replacement of the radial head, were reviewed retrospectively. Survival of the prosthesis was assessed from the radiographs of 37 patients after a mean follow-up of 50 months (12 to 107). The functional results of 31 patients were assessed using range-of-movement, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH) score and the RAND 36-item health survey. At the most recent follow-up 25 prostheses were still well fixed, nine had been removed because of loosening, and three remained implanted but were loose. The mean time from implantation to loosening was 11 months (2 to 24). Radiolucent lines that developed around the prosthesis before removal were mild in three patients, moderate in one and severe in five. Range of movement parameters and mass grip strength were significantly lower in the affected elbow than in the unaffected side. The mean MEPS score was 86 (40 to 100) and the mean DASH score was 23 (0 to 81). According to RAND-36 scores, patients had more pain and lower physical function scores than normal population values. Loosening of press-fit radial head prostheses is common, occurs early, often leads to severe osteolysis of the proximal radius, and commonly requires removal of the prosthesis.     

Radial head fractures with acute distal radioulnar dislocation. Essex-Lopresti revisited

Seven adults with displaced radial head fractures had concurrent dislocation of the distal radioulnar joint. Because support of the radius was lost at both the elbow and wrist, proximal migration of the radius from 5 to 10 mm occurred. Different types of fractures were classified to designate the best method of restoring radial length to prevent chronic wrist pain and stiffness. Type I fractures had large displaced radial head fragments with minimal or no comminution and amenable to interfragmentary fixation. Type II fractures had severe comminution requiring radial head excision and prosthetic replacement. Type III were old injuries with irreducible proximal migration of the radius managed by ulnar shortening and radial head prosthetic replacement. There were three Type I, two Type II, and two Type III fractures. Results of treatment were graded as 3, excellent; 2, good; 1, fair; and 1, poor. The three excellent results were in patients in which restoration of radial length was achieved within one week of injury. Suboptimal results occurred in the remaining four patients when definitive surgery was delayed four to ten weeks. The poor result was in a patient treated only by radial head excision and who refused further surgery. Recommendations include meticulous clinical and roentgenographic examination of the distal radioulnar joint in all patients with displaced radial head fractures. Preservation of the radial head with anatomic reduction and rigid internal fixation is preferred, but radial head replacement may be necessary in cases with extensive comminution. Radial head excision alone, though contraindicated, may be restructured by ulnar shortening and radial head prosthetic replacement.     

Longitudinal radioulnar dissociation

Proximal translation of the radius is a complication of radial head fractures that occurs in association with disruption of the longitudinal soft-tissue stabilizers of the forearm. The sequelae of this process include debilitating wrist and elbow pain secondary to ulnocarpal and radiocapitellar abutment as well as loss of grip strength. When radioulnar dissociation is recognized early, treatment involves prevention of proximal radial migration by preservation of the radial head and stabilization of the distal radioulnar joint. When primary bony repair of the radial head is not feasible, prosthetic replacement of the radial head is necessary to prevent proximal radial migration. Management is complex in chronic cases in which longitudinal radioulnar dissociation is diagnosed after radial migration has occurred. Treatment goals include normalization of the radioulnar relationship and prevention of further migration. Although several reconstructive treatment options are available, no clear solutions exist, and long-term prognosis is guarded. Therefore, early recognition of longitudinal forearm instability is critically important.     

Radial head replacement in capitellocondylar total elbow arthroplasty. 2- to 6-year follow-up evaluation in rheumatoid arthritis

We reviewed six capitellocondylar metal-to-plastic total elbow replacement prostheses with radial head components, implanted in patients with rheumatoid arthritis. At an average of 4.7 +/- 1.5 years, relief of pain, improvement of function, and a functional range of motion were preserved. Five of the six elbows (83%) were clinically rated good or excellent. Radiolucent lines were seen at the bone-cement interface in 50% of the humeral component stems and in all ulnar component boats within 2 years after surgery; none had progressed at subsequent examination. Most were less than or equal to 1 mm wide, and none were associated with clinical deterioration. Only one of the humeral components was radiographically loose. No radiolucent lines were seen along the stems of the ulnar or radial components. There were no postoperative dislocations when the radial component was used, presumably because the prosthetic radial head provided increased constraint. None of these elbows have required revision. Radial head replacement in capitellocondylar arthroplasty had been discontinued because radiolucent lines were observed at early review. However, the absence of clinical failure, dislocation, or progression of radiolucency at long-term follow-up examination favor radial head replacement in primary unconstrained total elbow arthroplasty.     

Flexible implant arthroplasty of the radiocarpal joint. Surgical technique and long-term study

The wrist joint is frequently impaired in rheumatoid, post-traumatic, and degenerative arthritis. Stable radiocarpal motion, even limited, can improve functional hand adaptations, especially if the proximal or distal joints are disabled. A flexible silicone intramedullary stemmed hinged implant was developed in 1967 to be used as an adjunct to resection arthroplasty of the radiocarpal joint while at the same time maintaining the radiocarpal relation and allowing wrist motion in all planes. The surgical technique includes proper contracture release, bone preparation, extensor tendon repair and balancing, and dorsal and palmar capsuloligamentous repair to allow only 60 degrees of total passive flexion/extension and 10 degrees radial/ulnar deviation. This procedure can be combined with ulnar head capping. Metal bone liners (grommets) may be used to protect the radiocarpal implant from sharp bone edges. From January 1970 to April 1983, 181 wrist implant procedures had been performed in 139 patients, most of whom had rheumatoid arthritis. Stable, pain-free functional motion was obtained in the majority of cases. Roentgenograms showed the implants to be well tolerated by bone. Complications were infrequent. Because this procedure does not require cementing or significant bone resection, revision or arthrodesis procedures are facilitated.     

Load-sharing at the wrist following radial head replacement with a metal implant. A cadaveric study

BACKGROUND: Surgical excision of the radial head is frequently required after a comminuted fracture of the radial head. The outcome of this procedure is often unpredictable, with some patients experiencing ulna-sided pain in the wrist secondary to proximal migration of the radius. Insertion of a radial head prosthesis could prevent proximal radial migration and restore normal load-sharing at the wrist. The thickness of the radial head implant is an important variable in restoring anatomical radial length; however, the effects of varying the length of implants that were used to reconstruct the radius on load-sharing at the wrist have not been studied biomechanically, to our knowledge. METHODS: A miniature load cell was attached to fifteen fresh-frozen cadaveric forearms to record force in the distal part of the ulna as the wrist was axially loaded to 134 N of compression force. Proximal displacement of the radius relative to the capitellum was also recorded. Loading tests on intact forearms were performed with the elbow in valgus and varus alignment and with three positions of wrist rotation (neutral, 45 degrees of pronation, and 45 degrees of supination). Loading tests were then repeated, with the same positions of varus and valgus elbow alignment and wrist rotation as had been used in the tests of the intact forearm, after radial head excision and subsequent insertion of metal radial head implants that restored anatomical length, implants that produced a radial length that was longer than the anatomical length, and implants that produced a radial length that was shorter than the anatomical length. Testing of these different implant thicknesses was repeated after sectioning of the interosseous membrane. RESULTS: The mean distal ulnar forces and mean proximal radial displacements following insertion of an implant that restored anatomical length were not significantly different from the corresponding values for the intact forearm. At neutral wrist rotation, replacing that implant with an implant that increased the radial length by 4 mm (after sectioning of the interosseous membrane) decreased the mean distal ulnar force from 13.4% to 3.3% of the applied wrist force with the elbow in valgus alignment and from 29.1% to 8.6% with the elbow in varus alignment. Replacing the implant that restored anatomical length with one that decreased the length by 4 mm (after sectioning of the interosseous membrane) significantly increased the mean distal ulnar force from 13.4% of the applied wrist load to 33.3% with the elbow in valgus alignment and from 29.1% to 51.6% with it in varus alignment. The mean distal ulnar forces were not significantly affected by the position of wrist rotation when the elbow was in valgus alignment. However, when the elbow was in varus alignment, the mean distal ulnar forces associated with all reconstructed radial lengths were significantly higher when the wrist was placed in 45 degrees of supination. CONCLUSIONS: In this cadaveric model, insertion of a metal implant maintained distal ulnar forces at normal levels, at all three positions of wrist rotation, when the radius had been restored to its original anatomical length. Distal ulnar forces and proximal radial displacements were significantly affected by the reconstructed length of the radius. CLINICAL RELEVANCE: Radial head implants are utilized to prevent proximal migration of the radius as the wrist is loaded; this is especially important when the interosseous membrane has been ruptured and thus cannot help to limit radial displacement. At the time of surgery, comminution and displacement of a radial head fracture may make estimation of the original radial length difficult. Our results demonstrate that, in terms of distal ulnar loading, it is preferable to insert an implant that is too thick rather than too thin.     

Die Behandlung der Radiusk?pfchentrümmerfraktur —Resektion oder Prothese?

Comminuted fractures of the radial head (Mason 3) are rare injuries. A successful osteosynthetic reconstruction is not possible. The common treatment of this fracture is the resection of the radial head, with instability or valgus deformity of the elbow joint, or a prosthetic replacement. Both methods are discussed controversially in literature. From 1986 until 1998 42 patients with comminuted radius head fractures were treated surgically (34 silastic prostheses, 8 resections). We controlled 31 patients clinically and radiologically at an average of 5 years after operative treatment. Using a modified score of Radin and Riseborough, we got in 84% good or fair results after prosthetic replacement. In one case the removement of the prosthesis was necessary because of displacement. By using the silastic prosthesis compared to the resection we saw a much better primary stability with resultant early functional movement of the elbow joint.      

Early results with osseointegrated proximal interphalangeal joint prostheses

Osseointegrated endoprostheses were used in 22 proximal interphalangeal joint replacements in 12 patients between 1993 and 1995. Indications for surgery were joint destruction due to rheumatoid arthritis (13 joints), primary osteoarthrosis (7 joints), posttraumatic arthrosis (1 joint), and psoriatic arthritis (1 joint). The prostheses consisted of 2 screw-shaped titanium fixtures with a flexible silicone spacer. The 1-stage surgical procedure included joint resection and cancellous bone grafting from the iliac crest before insertion of the titanium fixtures. At a follow-up examination 27 months (range, 12-37 months) after surgery, the average active range of motion was 56 degrees (20 degrees to 80 degrees) with an extension lag of 11 degrees (-5 degrees to 45 degrees), corresponding to an average arc of motion of from 11 degrees to 67 degrees flexion. Radiographs indicated that 41 of 44 fixtures were osseointegrated. Four of the 22 joint mechanisms showed fracture of the silicone spacer; deformation of the silicone was noted in an additional 27%. Patient satisfaction was high (20 of 22 joints), with significantly improved range of motion and hand function, increased grip strength, good pain relief, and satisfactory appearance. The results of this study indicate good early clinical findings using osseointegrated implants for proximal interphalangeal joint replacement but also show the need for further development regarding the durability of the flexible silicone joint spacer.     

Stability of the forearm after resection of the distal ulna and proximal radius in rheumatoid arthritis: report of 11 cases

Combined resection of radial head and distal ulna could jeopardize the stability and kinematics of the forearm bones. The goals of this retrospective study was to investigate these data after resection of distal ulna and proximal radius in rheumatoid arthritis. Between 1990 and 1998, eleven patients had these bone resections combined with implantation of elbow prostheses (eight Kudo and three GSB III). Wrist surgery consisted in five wrist arthrodeses combined with Darrach procedure, four Sauvé-Kapandji procedures and two isolated Darrach procedures. Mean age at surgery was 58 years and the average follow-up was 40 months. We assessed at follow-up: 1) wrist and elbow pain according to Gschwend; 2) stability of the forearm bones (cubitus valgus angle, impingement of the proximal radial stump with humerus, giving away accident of the ulnar distal stump); 3) wrist and elbow mobility. At follow-up six patients had no pain at the elbow and five had slight occasional pain. At the wrist, five patients had no pain and six slight occasional pain. Elbow motion was increased (from mean 83 degrees [50 degrees-100 degrees] to mean 110 degrees [85 degrees-135 degrees]) excepted in supination which slightly decreased (from mean 3 degrees [40 degrees-90 degrees] to mean 75 degrees [85 degrees-90 degrees]). Mean wrist mobility was impaired because of the five combined radiocarpal arthrodeses. If these five wrist arthrodeses were excluded, the mean ranges of motion were: 10 degrees in flexion, 16 degrees in extension, 2 degrees in radial deviation, 14 degrees in ulnar deviation. At follow-up, no patient had giving away accident of the ulnar distal stump nor impingement between radial stump and humerus in full flexion. Average cubitus valgus was 10 degrees. This study pointed out the predominant effect of the interosseous membrane in stability of the forearm bones.     

Radio-ulnar dissociation. A review of twenty cases.

The results of treatment were reviewed for twenty patients who had sustained concomitant injuries of the lateral compartment of the radiohumeral joint and the ipsilateral distal radio-ulnar joint. The ages of the patients ranged from eight to seventy-four years (average, thirty-five years) and the duration of follow-up ranged from four months to twenty-seven years (average, 113 months). In fifteen patients, the injury of the wrist was diagnosed after a mean delay of seven years and eleven months (range, one month to twenty-six years). In all fifteen, the radial head injury was treated by excision, either initially or after some delay. After excision of the radial head, all fifteen patients complained of severe pain at the distal radio-ulnar joint. The results, on the basis of elbow and wrist scores of fair or better without complications, were satisfactory in only three patients. In the remaining five patients, in whom the injuries of both the elbow and the wrist had been identified at the initial evaluation, the radial head was either preserved or replaced. The results, on the basis of elbow and wrist scores of fair or better, were graded as satisfactory in four of these patients. Our data show that any injury to the lateral side of the elbow should prompt a careful evaluation of the ipsilateral distal radio-ulnar joint for associated instability.     

The sequelae of a missed Essex-Lopresti lesion

Radial head fractures are the most common type of elbow fracture in adults. Unrecognised disruption of the intraosseous membrane at the time of injury can lead to severe wrist pain from proximal radial migration especially if the radial head is excised. In this case, despite anatomical reduction and internal fixation of the radial head fracture, longitudinal forearm instability developed after delayed radial head resection was performed 7 months post-injury. A Suave-Kapandji procedure was performed due to ongoing wrist pain. Because of the previous radial head resection, this led to a floating forearm that could only be solved by creating a one-bone forearm, sacrificing all forearm rotation to achieve a stable lever arm between the elbow and wrist joint.     

Effects of radial head excision and distal radial shortening on load-sharing in cadaver forearms

BACKGROUND: The present study was performed to measure changes in radioulnar load-sharing in the cadaveric forearm following two orthopaedic surgical procedures that often have varying results: radial head excision and distal radial shortening. A better understanding of the biomechanical consequences of those procedures could aid surgeons in obtaining a more satisfactory clinical outcome. METHODS: Miniature load-cells were inserted into the proximal part of the radius and the distal part of the ulna in twenty fresh-frozen cadaveric forearms. Load-cell forces, radial head displacement relative to the capitellum, and local tension within the central band of the interosseous membrane were measured simultaneously as the wrist was loaded to 133.5 N in neutral pronation-supination and neutral radioulnar deviation. Testing was repeated after incremental distal radial shortening and after removal of the radial head. RESULTS: With the elbow flexed to 90 degrees and in valgus alignment (the radial head in contact with the capitellum), the mean force in the distal part of the ulna was 7.1% of the applied wrist force and the mean force in the interosseous membrane was 4.0%. With the elbow in varus alignment (a mean initial gap of 1.97 mm between the radial head and the capitellum), the respective mean values were 27.9% and 51.2%. After excision of the radial head, the mean force in the distal part of the ulna increased to 42.4% of the applied wrist force and the mean force in the interosseous membrane increased to 58.8%, in both varus and valgus elbow alignment. The mean distal ulnar force increased with progressive distal radial shortening in both varus and valgus elbow alignment; after 6 mm of radial shortening, the distal ulnar force averaged 92.4% (in varus alignment) and 60.9% (in valgus alignment). Equal distal load-sharing between the radius and ulna occurred after approximately 5 mm of radial shortening with the elbow in valgus alignment and after approximately 2 mm of radial shortening with the elbow in varus alignment. In valgus alignment, the force in the interosseous membrane was negligible after all degrees of radial shortening; in varus alignment, the mean force in the interosseous membrane decreased from 51.2% (0 mm of distal radial shortening) to 0% (6 mm of distal radial shortening) because of progressive slackening of the interosseous membrane. CONCLUSIONS: Radial head excision shifted the applied wrist force that normally would be transmitted to the elbow, through radial head-capitellar contact, to the interosseous membrane. The resulting proximal radial displacement created an ulnar-positive wrist and increased distal ulnar loading. Radial shortening and ulnar lengthening procedures have been designed to shift the applied wrist force from the distal part of the radius to the distal part of the ulna; it is commonly assumed that these procedures have equivalent biomechanical effects. We found that radial shortening resulted in slackening of the interosseous membrane, thereby negating its ability to transmit load through the forearm. Slackening of the interosseous membrane would not be expected with distal ulnar lengthening procedures. CLINICAL RELEVANCE: When the radial head has been fractured or excised, the mechanical status of the interosseous membrane is critical to the load-sharing process. If the interosseous membrane remains intact, distal ulnar loads will be limited to less than half of the applied wrist force; if the interosseous membrane has been damaged, nearly the entire applied wrist force will be shifted to the ulna. The amount of radial shortening or ulnar lengthening performed at the time of surgery during joint-leveling procedures has been largely empirical. We found that distal ulnar load increased by approximately 10% for each millimeter of radial shortening.     

急性桡骨头骨折合并桡尺远侧关节脱位的诊断和治疗

目的 研究急性桡骨头骨折合并桡尺远侧关节脱位(Essex-Lopresti损伤)的诊断和治疗特点.方法 自2002年至2009年,我科共诊治了3例Essex-Lopresti损伤的患者.对桡骨头骨折进行固定修复或假体置换,对桡尺远侧关节损伤进行复位和内固定.对3例患者都进行了随访和疗效评估.结果 经过15～48个月的随访,肘关节和腕关节评分系统评定显示术后所有患者的前臂功能恢复效果满意.结论 急性Essex-Lopresti损伤的治疗原则是修复或假体置换桡骨头骨折,同时复位、固定桡尺远侧关节.如桡骨头骨折粉碎严重不能进行内固定,不可以行切除术,否则将导致严重后果.

Abstract：

Objective To study the methods of diagnose and treatment of acute radial head fracture accompanied by distal radioulnar joint dislocation (Essex-Lopresti injury). Methods From 2002 to 2009,3 patients with acute Essex-Lopresti injury were diagnosed and treated in our department. Radial head fractures were treated with fixation repair or radial head prosthesis replacement. Distal radioulnar joint dislocations were treated with reduction and fixation. All three patients were followed-up and the effects were assessed. Results Total time of follow-up ranged from 15 to 48 months. According to the elbow joint and wrist joint scoring systems,results of postoperative functions were satisfactory. Conclusion Acute Essex-Lopresti injuries should be treated with radial head fracture fixation or replacement,and simultaneous reduction and fixation of the dislocated distal radioulnar joint. When fracture of the radial head is too comminuted to be repaired,simple resection of the radial head is not an option since it will result in failure.     

Nonunion of radial neck fracture: An unusual differential diagnosis of tennis elbow,a case report

A 67-year-old woman was referred because of persistent pain in her dominant right elbow. She had been treated for lateral epicondylitis and nonspecific wrist pain by intraarticular corticosteroid injection in the wrist and by physiotherapy for 2 years. The pain occurred during straining and with pro- and supination movements and had started after a fall on the right hand. Radiographs of the wrist were normal. There was full flexion and extension in the elbow joint and normal pro- and supination. There was tenderness on palpation of the lateral epicondyle. Resisted extension of the wrist was slightly painful, but grip strength was normal. Radiographs of the elbow showed an atrophic pseudarthrosis of the radial neck (Figure 1).     

应用保留桡骨头桡骨颈节段性截骨治疗创伤后上尺桡关节骨性融合的早期疗效

目的探讨保留桡骨头的桡骨颈节段性截骨治疗创伤后上尺桡关节骨性融合的早期疗效。方法回顾分析2017年1月至2019年5月广州医科大学附属第二医院创伤骨科采用保留桡骨头的桡骨颈节段性截骨术治疗的创伤性上尺桡关节骨性融合患者7例的临床资料。其中男5例,女2例;年龄为(35±11)岁(19~60岁)。患肢均为右侧。评价术前与随访时患肢前臂旋转活动度、肘和腕关节疼痛程度、握力以及尺骨变异程度和截骨处异位骨化情况并进行比较。采用SPSS 18.0软件对数据进行处理。结果随访(4±0.4)个月(2~6个月)。术前与术后3个月前臂旋转活动度分别为(43±14)°(15°~51°)和(120±31)°(111°~134°),差异有统计学意义(P=0.012);握力分别为(25.5±10.3)kg(21.2~28.6 kg)和(26.3±11.1)kg(21.7~28.4 kg),差异无统计学意义(P=0.074);尺骨变异分别为(-0.13±0.04)mm(-0.15^-0.07 mm)和(-0.12±0.09)mm(-0.14^-0.08 mm),差异无统计学意义(P=0.081)。所有患者术前与术后肘关节与腕关节未见疼痛,术后未见截骨处异位骨化形成。结论应用保留桡骨头的桡骨颈节段性截骨治疗创伤后上尺桡关节骨性融合,方法简单,早期疗效令人满意。     

Ulnocarpal abutment after wrist arthrodesis

We report three patients aged from 22 to 34 years, in whom ulnocarpal abutment developed after wrist arthrodesis. Two were treated by excision of the triquetrum and one by excision of the pisiform. The three patients were seen after wrist fusion because of ulnar wrist pain on forearm rotation, which was relieved by excision of a carpal bone. Two patients had had wrist arthrodesis because of wrist pain resulting from degenerative arthritis and silicone synovitis resulting from silicone rubber replacement of the lunate as treatment for Kienb?ck's disease. One patient had had a wrist arthrodesis to treat degenerative arthritis after an intra-articular distal radius fracture. The arthrodeses were all done with an A. O. plate and iliac crest bone graft. One patient gained forearm rotation after the excision of the carpal bone and none of the patients lost rotation. The average follow-up was 16 months.     

Early failure of silicone radial head implants in the rheumatoid elbow. A complication of silicone radial head implant arthroplasty

Three cases of early recurrent synovitis of the rheumatoid elbow following silicone radial head implant arthroplasty are presented. All three patients underwent synovectomy with silicone radial head implant for pain and loss of function due to rheumatoid synovitis. All three implants failed within 4-9 months after surgery. This failure was associated with radiographic medial joint space widening. At reexploration, recurrent synovitis with hemosiderin pigmentation was noted. Patterns of prosthetic failure included fracture, fraying, and compressive deformation or rotary wear ("motar and pestle") of the silicone radial head; a prosthetic stem fracture was also present. Histologic examination of the synovium revealed evidence of silicone-induced synovitis; particulate, refractile silicone debris was associated with inflammatory and foreign body giant cells. The presence of rheumatoid destruction of the joint surface may have accelerated this process and may be a relative contraindication to silicone radial head implant arthroplasty.