The effect of the radial head and prosthetic radial head replacement on resisting valgus stress at the elbow

Five fresh nonembalmed elbows were tested for resistance to valgus stress in their anatomic state, after radial head resection, and after insertion of Silastic and polymethylmethacrylate (PMMA) radial head replacements. The resistance to valgus stress was found to be reduced an average of 28% after radial head resection. The PMMA and Silastic implants restored valgus stiffness an average of 86% and 78% respectively, as compared to intact elbow values for corresponding flexion angles. Testing in pronation, supination and neutral forearm rotation demonstrated no difference in valgus stiffness. For each elbow, resistance to valgus stress was greatest at full extension and dropped approximately 30% at all other flexion angles as compared to corresponding full extension value. These data support the concept of the radial head as a stabilizer to valgus stress in the in vitro elbow. Further, this data demonstrated the ineffectiveness of current radial head replacement systems in restoring this biomechanical function and suggest that the use of a stiffer implant material may be beneficial in resisting valgus stress. Additional testing is indicated to determine the performance of a stiffer implant at the clinical and biological levels.     

Radial head fracture in the medial collateral ligament deficient elbow; biomechanical comparison of fixation, replacement and excision in human cadavers

A widely used clinical recommendation is that in the presence of medial collateral ligament injuries, two-part radial head fractures should be fixed rather than excising or replacing the radial head. Direct biomechanical data comparing fracture fixation, radial head replacement and excision in a human cadaveric elbow model, have not been previously described. Such comparison is clinically important as with the increasing availability of radial head implants and promising follow up results, the role of radial head replacement in fracture management may have to be redefined. In this study, five fresh cadaveric elbows had radial head fracture creation and medial collateral ligament division, fracture fixation, radial head replacement and excision. Valgus and varus laxity were determined using an electromagnetic tracking system. Radial head replacement leads to a similar valgus (P=0.80) [corrected] laxity as compared to radial head fixation. Radial head excision resulted in a significantly greater valgus laxity as compared to radial head fixation (P=0.02) or replacement (P=0.03). Both radial head excision and replacement led to a greater varus laxity as compared to fixation. Our results suggest that in the elbow with medial collateral ligament injury and two-part radial head fracture, fixation is overall biomechanically superior as compared to replacement and excision.     

Laxity of the elbow after experimental excision of the radial head and division of the medial collateral ligament. Efficacy of ligament repair and radial head prosthetic replacement: a cadaver study

We studied the stabilising effect of prosthetic replacement of the radial head and repair of the medial collateral ligament (MCL) after excision of the radial head and section of the MCL in five cadaver elbows. Division of the MCL increased valgus angulation (mean 3.9 +/- 1.5 degrees) and internal rotatory laxity (mean 5.3 +/- 2.0 degrees). Subsequent excision of the radial head allowed additional valgus (mean 11.1 +/- 7.3 degrees) and internal rotatory laxity (mean 5.7 +/- 3.9 degrees). Isolated replacement of the radial head reduced valgus laxity to the level before excision of the head, while internal rotatory laxity was still greater (2.8 +/- 2.1 degrees). Isolated repair of the MCL corrected internal rotatory laxity, but a slight increase in valgus laxity remained (mean 0.7 +/- 0.6 degrees). Combined replacement of the head and repair of the MCL restored stability completely. We conclude that the radial head is a constraint secondary to the MCL for both valgus displacement and internal rotation. Isolated repair of the ligament is superior to isolated prosthetic replacement and may be sufficient to restore valgus and internal rotatory stability after excision of the radial head in MCL-deficient elbows.     

人工桡骨头置换治疗肘关节不稳定的桡骨头粉碎性骨折

目的探讨钛制人工桡骨头置换治疗肘关节不稳定的桡骨头粉碎性骨折的疗效。方法自2000年1月至2003年8月采用钛制人工桡骨头置换治疗肘关节不稳定的桡骨头粉碎性骨折18例,男13例,女5例;年龄24～47岁,平均34.8岁。左侧8例,右侧10例。合并同侧肘关节其他骨折3例,其中桡骨近端粉碎性骨折1例,尺骨冠状突骨折2例;合并同侧上肢其他部位骨折4例,其中桡骨远端骨折3例,肱骨外科颈骨折1例。按Mason分型,Ⅲ型10例,Ⅳ型7例,Essex-Lopresti损伤1例;所有患者均为闭合性损伤,除4例为伤后3周以上的陈旧性骨折脱位外,其余均为伤后2周内的新鲜损伤。伤后至手术的时间平均为9d(4～26d)。结果术后平均随访29个月(12～44个月)。按Broberg和Morrey评估标准进行功能评定,优8例(44.4%),良8例(44.4%),可1例(5.6%),差1例(5.6%),优良率为88.9%。未见切口感染、神经损伤、金属异物反应、肘外翻增大及腕部畸形等并发症。X线片显示置换的桡骨头假体稳定,未发现桡骨短缩、上移和下尺桡关节半脱位。假体的生物相容性良好,未见炎性反应和金属异物反应。6例肘部有轻度异位骨化,但未对肘和前臂的运动造成明显影响。结论钛制人工桡骨头置换治疗肘关节不稳定的桡骨头粉碎性骨折可获得比较满意的疗效。     

Results of acute excision of the radial head in elbow radial head fracture-dislocations

OBJECTIVES: To evaluate the results of radial head excision for the treatment of elbow fracture-dislocations with an unsalvageable comminuted radial head fracture and no other associated fractures. DESIGN: Retrospective study. SETTING: University Hospital. PATIENTS AND INTERVENTION: Ten elbow fracture-dislocations with a comminuted radial head fracture treated with radial head excision in our institution between 1990 and 1996 and followed a mean of 4.62 years. MAIN OUTCOME MEASUREMENTS: Clinical results were graded using the Mayo index and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Radiographs were evaluated for proximal radius migration, elbow angulation, degenerative changes, and ectopic bone. RESULTS: Final clinical results were excellent in four patients, good in five patients, and fair in one patient. Pain was absent in six patients, mild in three patients, and moderate in one patient. Mean flexion arc was 7.5 to 140 degrees, and mean pronation and supination were 85.5 and 83.5 degrees, respectively. Average strength loss was 15 percent. No elbow was unstable. The raw DASH score ranged from 39 to 62 points (normalized values, 0.66 to 15,79 points). On average, the carrying angle increased 5.4 degrees. Degenerative changes were absent in two, Grade I in four, and Grade II in four patients. Ectopic bone, mainly residual fracture fragments, was evident in four patients. Proximal migration of the radius averaged 1.6 millimeters; the two patients with over four millimeters of migration had mild wrist pain. CONCLUSIONS: Acute radial head excision for the treatment of elbow fracture-dislocations provides satisfactory short-term clinical results when there are no other associated intraarticular fractures. However, the long-term significance of the early degenerative changes is not known.     

Fracture of the radial head with associated elbow dislocation: results of treatment using a floating radial head prosthesis

OBJECTIVES: To assess elbow function, complications, and problems of radial head fractures associated with elbow dislocation receiving surgical treatment with a floating prosthesis. DESIGN: Prospective clinical study. SETTING: University Hospital, Orthopaedic Department, Sart Tilman, Liège, Belgium. PATIENTS: Eleven consecutive adult patients were treated with a floating prosthesis for acute radial head fractures associated with elbow dislocation from January 1994 to September 1996. INTERVENTION: The floating radial head prosthesis (Tornier SA, Saint-Ismier, France) was used in all our patients. The implant is in two parts: a radial head made of high-density polyethylene enclosed in a cobalt-chrome cup, which articulates in a semiconstrained manner with the spherical end of a cemented intramedullary stem. The implants were inserted within the first week following the injury (range 2 to 7 days). Three cases also required internal fixation of the coronoid process of the ulna; in one case plate fixation of an olecranon fracture was also performed. MAIN OUTCOME MEASUREMENTS: Patients were assessed by physical examination, a functional rating index (Morrey et al.), and radiographs. The parameters evaluated were motion, stability, pain, and grip strength. Potential complications such as infection, prosthetic failure, or dislocation were investigated. RESULTS: The minimum follow-up time was two years (mean 32 months, range 24 to 56 months). Four patients were considered to have excellent results, four patients were considered to have good results, two patients had fair results, and one patient had a poor result. There were no cases of infection, prosthetic failure, or dislocation. No patient required prosthetic revision. CONCLUSION: The basic principle of maintaining anatomic and physiologic relationships applies when deciding on treatment for radial head fractures with associated elbow dislocation. The loss of lateral osseous support will render the elbow grossly unstable. We believe that a floating prosthesis may be indicated in Mason Type III radial head fractures associated with elbow dislocation, especially in the presence of associated destabilizing fractures. Well-controlled comparative randomized studies will be needed to delineate the optimal treatment for a given situation.     

Use of a polymethacrylate radial head spacer in temporary reconstruction of complex radial head fracture with associated elbow instability

Radial head replacement in complex elbow fractures (Mason III) with either bony or ligamentous injuries or interosseous membrane rupture is unquestionable. Actual modular and metallic prosthesis ease the mounting technique and ensure durability. Nevertheless, these types of prostheses are not always available in a short time in our daily practice. We present the use of a transient polymethacrylate spacer as an alternative in nonreconstructable complex radial head fractures with a unstable elbow. We assessed 38 patients between 2006 and 2007, with a median follow-up of 53.8 months. We included 14 Mason IV; 8 Monteggia (posterior); 7 Mason III with either associated medial collateral ligament or interosseous membrane injury; 6 elbow triads; and 3 Essex-Lopresti lesions. With the Mayo elbow performance score and the disabilities of the arm, shoulder, and hand score questionnaire, we assessed the functionality. Anatomic results were evaluated with x-ray scans of the elbow and wrist using the Broberg and Morrey and the Knirk and Jupiter scales. Functional results were as follows: 14--excellent, 14--good, 8--fair, and 2--poor. Assessment through disabilities of the arm, shoulder, and hand score questionnaire was 18.7% in average. There was a statistically significant relationship between joint stability and motion. Of the patients, 70% showed mild or moderate chondromalacia of the capitellum and 90% showed osteolysis on the proximal metaphysis of the radius, both events related to follow-up time but not to pain or range of movement. Of the cases, 30% showed heterotopic calcifications and 35% showed moderate arthrosis between the ulna and the humerus. None of the patients presented wrist arthrosis. Complications were 1 deep infection and 1 spacer luxation because of fatigue and ulna plate rupture (Monteggia posterior). In 6 patients, we had to remove the spacer because of pain and/or functional limitation, and 2 of these patients remained with moderate valgus instability after removal. We consider using this type of spacer in those complex situations in which the definitive prosthesis is not available, because it is cheap and resistant to axial and valgus forces. In spite of the good anatomic and functional results obtained and the low complication rate, we firmly think that the spacer should only be used in a transient manner and in special situations, although in this series, only 8 of the 38 patients have accepted to have the spacer removed.     

From radial head to radiocapitellar to total elbow replacement: A case report

IntroductionRadiocapitellar arthroplasty represents a possible treatment option for isolated osteoarthritis of the radial column. We report the first case of early failure of this procedure.Presentation of caseWe present the case of a 41-year old male who sustained a terrible triad injury to his right elbow and subsequently underwent radial head arthroplasty. Due to overstuffing of the radial head prosthesis, capitellar erosion occurred and radiocapitellar arthroplasty was thus performed. Only one year later, conversion of the radiocapitellar replacement to total elbow arthroplasty was required as a result of progressive ulnohumeral osteoarthritis.DiscussionAccording to the currently limited clinical data, radiocapitellar arthroplasty provides satisfactory results. However, biomechanical analysis shows that available prostheses do not sufficiently reproduce the radiocapitellar anatomy. The design of the prosthesis might thus have contributed to the rapid progression of ulnohumeral erosion following radiocapitellar arthroplasty although the poor outcome may also be attributed to the trauma itself along with the inadequate initial treatment.ConclusionsThe indication for radiocapitellar arthroplasty warrants careful consideration given the results of biomechanical analysis and the early failure due to progressive ulnohumeral erosion seen in the present case.     

Fractures of the radial head associated with dislocation of the elbow

Fractures of the radial head associated with dislocation of the elbow constitute a pathology for which it is difficult to choose treatment, and that has a high failure rate. A retrospective study of the literature and of a series of cases was conducted: 31 patients came to our observation between 1990 amd 2001 and were analyzed by clinical (Broberg and Morrey Score and SECEC Score) and radiographic testing. Based on the Broberg and Morrey Score the results were excellent in 4 patients (13%), good in 8 (26%), fair in 12 (39%), and poor in 7 (22%) with a success rate of 39% and a failure rate of 61% principally due to secondary stiffness and instability. In an attempt to reduce the number of failures, a treatment protocol aimed at restoring a stable, mobile and painless elbow was devised.     

桡骨小头假体置换治疗桡骨小头骨折

目的报告双极桡骨小头假体置换治疗严重桡骨小头粉碎性骨折的初步临床结果。方法自2002年8月～2005年6月采用双极人工桡骨小头假体(浮动杯假体)置换的方法治疗MasonⅢ、Ⅳ型桡骨小头骨折10例,新鲜骨折9例,陈旧性骨折1例。结果所有患者随访6～40个月,平均14.9个月,肘关节屈伸平均133.5°/9.0°,前臂旋前/旋后平均78.5°/84.0°,3例遗留肘关节轻度疼痛,1例肘关节轻度外翻不稳,3例肘关节轻度乏力。Broberg-Morrey肘关节功能评分平均93分,优6例,良3例,可1例,优良率为90%。结论双极桡骨小头假体置换治疗难以重建的桡骨小头骨折的近期效果满意,远期疗效有待进一步随访。     

Radial head prosthesis after fracture of radial head with associated elbow instability

Introduction: Fractures of the radial head and associated elbow instability can be treated with operation with radial head prosthesis. In this study, we evaluate function 1–7 years after implantation and also function after removal of five prostheses. Material and methods: Eighteen patients with radial head fracture and associated elbow instability were evaluated 3.7 years (1–7) after implantation of a radial head prosthesis. Pain at rest and during activity was measured with a visual analogue scale (VAS). Test of stability and neurological examination was done manually as well as measurement of the range of motion, using a goniometer. Activity of daily living (ADL) was estimated using five questions where the answers were graded between 1 and 3. The patients were asked to grade their general satisfaction according to the following scale; very satisfied, satisfied, not satisfied, disappointed. Plain X-rays were taken and 14 patients agreed to have their elbow strength evaluated using the validated BTE work simulator. Results: Five prostheses had been extracted due to poor range of motion. All these patients improved after extraction. All elbows were stable. No patient with extracted prosthesis had VAS score >2. The mean extension defect for this group was 15° (5–25) compared to the mean extension defect for the 13 patients with the prosthesis still in place 15° (0–40). The highest VAS score for the patients with prosthesis was five but the mean as low as 0.8. In the whole group, 13 patients were pain free. ADL function was good in general. The X-rays of the prostheses, still in place, showed radiolucent lines in 7 of the 13 patients. In the whole group, there was a significant decrease in supination, flexion and extension strength (P<0.01, P<0.01, P<0.05). Discussion: Radial head prosthesis works as a spacer after fracture of the radial head and associated instability. If range of motion is much restricted post-operatively, the prosthesis can be removed with improved function as result.     

Arthroscopic radial head excision in managing elbow trauma

Purpose

This study describes a case series of 15 patients with radial head fractures who underwent radial head excision using an arthroscopic technique.

Methods

Over a four year period, 15 patients (average age 49.6 years) who had sustained a radial head or radial neck fracture underwent an arthroscopic excision of the radial head. Four patients had an unreconstructable comminuted fracture (early group; EG) and 11 patients had pain and loss of motion with an associated non- or malunion (late group; LG).

Results

The mean time to surgery following injury was three weeks (one to five) for the EG and 27 weeks (eight–58) for the LG. The average visual analogue scale (VAS) was 1.7 (zero to four), and the average Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) score was 24.7 (16–44). At final follow-up, average supination was 62.0° (range 45–75°) and pronation was 63.3° (range 45–75°). There were no complications.

Conclusion

This series demonstrates that arthroscopic excision of fractures of the radial head and neck is reliable, reproducible and safe, with similar results to open excision. There may also be additional benefits in the short term with regards to speed of healing and rehabilitation.     

人工桡骨头置换术治疗桡骨头粉碎性骨折

目的 :探讨人工桡骨头假体置换术治疗桡骨头粉碎性骨折的近期疗效。方法:自2011年6月至2015年6月,采用人工桡骨头置换术治疗桡骨头粉碎性骨折25例,男10例,女15例;年龄24~61岁,平均40岁。分析不同时期患者患肢肘关节功能恢复情况,与健侧比较肘关节的活动度情况及末次随访时患侧肘关节功能评价情况。结果:25例均获随访,时间12~48个月,平均26个月,无感染、肘关节不稳定、下尺桡关节半脱位、骨化性肌炎等并发症发生。术后6、9个月及末次随访患者的VAS疼痛评分、Broberg和Morrey肘关节功能评分与术后3个月比较均改善(P0.05)。肘关节的屈伸活动度、旋转活动度在术后3、6、9个月与健侧差异有统计学意义(P0.01),但末次随访时与健侧比较差异无统计学意义(P0.05)。末次随访时根据Broberg和Morrey肘关节功能评分标准,优16例,良7例,可2例。结论 :人工桡骨头置换术治疗无法修复的桡骨头粉碎性骨折,能最大程度恢复肘关节的稳定性,早期进行功能锻炼,预防和减少并发症的发生,近期疗效满意,远期疗效待进一步观察。