Radial head replacement with a pyrocarbon head prosthesis: preliminary results of a multicentric prospective study

The authors present the preliminary results of a multicentric prospective study of 30 cases treated by a new radial head prosthesis (MoPyc). This new modular radial head prosthesis is composed of a cementless titanium stem and a 15° angulated neck. The head is in pyrocarbon and enables an optimal couple of friction between the implant and cartilage. This multicentric prospective study includes 30 patients (19 men and 11 women, mean age 50 years). The mean follow-up was 18 months (6–29 months). The main etiology was a radial head fracture with elbow instability. The post-operative evaluation was clinical and included the Broberg–Morrey score and the Mayo Clinic Elbow Performance Score (MEPS). The radiological evaluation included the stability of the elbow, the fixation of the prosthesis and the interface between the pyrocarbon head and the humeral condyl and the distal radio-ulnar joint. At the time of follow-up, the average Broberg–Morrey score was 88/100, with 77% of good and excellent results. The average MEPS was 95/100, with 97% of good and excellent results. Elbow flexion averaged 122°, extension −15°, pronation 74° and supination 72°. Elbow stability was good in all the cases, and no proximal migration of the radius occurred. Asymptomatic bone lucencies were found in five cases (three stress shieldings, under the neck of the prosthesis, two around the stem). Complications included two cases of proximal radio-ulnar synostosis and one under stuffing of the prosthesis (which was re-operated shortly after the first implantation) with a good final result. One case demonstrated a tendency to posterior subluxation during heavy work. The preliminary results of 30 patients treated by this radial head prosthesis with a pyrocarbon head are encouraging at a follow-up of 18 months. The shape and the modularity of this prosthesis provide a good stability and function of the elbow and allow an easy implantation regardless of the level of resection. The contact between the articular surfaces and the pyrocarbon head should ensure the durability of this arthroplasty. However, a longer follow-up is required.

人工桡骨头置换治疗桡骨头粉碎性骨折

目的探讨应用单极人工桡骨头假体置换治疗MasonⅢ、Ⅳ型桡骨头骨折的疗效。方法对15例MasonⅢ、Ⅳ型桡骨头骨折患者应用人工桡骨头假体进行置换并观察疗效。结果 15例均获随访,时间6～30个月。按Mayo肘关节功能评分评定：优9例,良5例,可1例。无感染发生。结论桡骨头在稳定肘关节及上尺桡关节中起着至关重要的作用,桡骨头骨折如不能修复,假体置换是更好的选择。     

Radial head prosthesis with a mobile head

Radial head replacement is a useful method in the treatment of comminuted radial head fractures. Because such injuries are a common clinical problem and many complications have been reported after radial head replacements, a new radial head prosthesis is proposed. This new design, based on the shape-dimensional identification of the radial head, consists of two parts. The head, made of ultra-high molecular weight polyethylene, is articulated with a Vitallium stem. A series of functional quality and strength tests were conducted on this new prosthetic design. The implant was also examined via the finite element method. General preclinical investigations of clinical cases show that this prosthesis is a very promising design.     

Comminuted radial head fractures treated with pyrocarbon prosthetic replacement

Purpose  

We had evaluated our experience in the treatment of displaced and comminuted radial head fractures with pyrocarbon radial head prosthesis.     

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。     

Radial head prosthesis: results overview

Background/purpose

Radial head replacement is frequently used in treatment of radial head fractures or sequela. Impossibility to restore a correct anatomy, acute elbow traumatic instability and failure of osteosynthesis hardware are the most common indications. The authors describe their case studies and results on the implantation of various radial head prostheses.

Materials

Between June 2005 and June 2016, 28 radial head prostheses were implanted in the same number of patients with an average follow-up of 49 months (6–104). Indications for implantation were: Mason type III and IV radial head fractures and post-traumatic arthritis due to failure of previous treatments. Monopolar prostheses were used and were press-fit implanted via Kaplan’s lateral access and Kocher’s anconeus approach to the humeroradial joint. At the follow-up, assessments were made of the pain, according to the visual analogic scale, range of motion (ROM), stability and functionality according to the Mayo Elbow Performance Score, presence of osteolysis and mobilization during radiography tests, personal satisfaction of the patients, Disabilities of the Arm, Shoulder and Hand and Patient-Rated Wrist Evaluation outcomes measurements.

Results

At the follow-up, we recorded an average level of pain of 1.8 in patients under acute treatments for radial head fractures and a marked reduction in the remaining cases from 6.7 to 2.1. ROM was found on average to be 107° of flexion–extension and 159° of pronosupination. Personal satisfaction was good–excellent in 23 cases. There was no case of infection; removal of the implant was necessary in three cases due to mobilization of the stem and oversized implants. In six cases, bone resorption was seen at the level of the prosthetic collar and it was in all cases asymptomatic.

Conclusions

The results of this study suggest that the use of prostheses, if well positioned, is a valid solution in the treatment of secondary arthritis and fractures of the radial head with poor prognosis, with good results in the reduction of pain, recovery of movement and improved quality of life.

     

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.     

Radial head prosthesis: surgical tips and tricks

Radial head prostheses (RHP) have been developed to decrease the complications rate following a radial head resection surgery. The aim of the RHP is to replicate the physiological radiocapitellar tracking, reproducing the mechanical function of the native radial head: to stabilize the elbow and to shear the forces passing through the elbow along with the other stabilizers. The currently used RHP models try to achieve this target with three different prosthesis’ strategies: (a) loose fit stem, (b) bipolar radial head or (c) anatomical radial head. Even if the radial head fixation is the preferred technique in every possible case and the resection can be still considered a possible option, in the last years there has been a growing worldwide consensus in using the radial head replacement in patients with unfixable radial head fractures, especially if associated with complex elbow instability. However, complications after a RHP are not uncommon, and their rate is raising as long as the implants number are increasing. The main difficulties are due to the implantation technique that needs to be performed with the same attention and precision used for the replacement of all the other joints, and to the concurrent treatment of the associated lesions. A personalized postoperative rehabilitation program is essential for obtaining good results and decreasing the complications rate. Concern exists for the young age of the patients that often require a RHP: personal experience and literature analysis suggest that if the clinical and radiographic results are positive after a 6–12-month follow-up, good outcomes can be also expected at a medium- or long-term follow-up.     

Capitate pyrocarbon prosthesis in radiocarpal osteoarthritis

Scapholunate dissociation or scaphoid pseudarthrosis may lead to osteoarthritis of the wrist. When osteoarthritis affects the midcarpal joint, proximal row carpectomy is no longer possible and only 4 corners fusion or capitolunate arthrodesis may be indicated. However, in some cases, osteoarthritis or bone necrosis may involve the lunatum, making partial arthrodeses impossible. Total arthrodesis may be proposed in such cases, but with a loss of range-of-motion. Total prosthesis may be considered but the results of this procedure are not always encouraging. Consequently, in these situations, we perform pyrocarbon prosthesis implant, replacing the head of the capitatum. This article describes the procedure and the results of a preliminary study.     

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。     

桡骨头置换术治疗桡骨头严重粉碎性骨折

目的探讨桡骨头置换术治疗桡骨头严重粉碎性骨折的疗效。方法 2006年6月至2009年2月行桡骨头置换术治疗6例桡骨头严重粉碎性骨折患者,男4例,女2例;年龄24～36岁,平均27.6岁;均为MasonⅢ型、Ⅳ型。结果术后6例患者全部获得随访,随访时间为4～36个月,平均27个月。除1例患者活动时外侧有摩擦感、轻度疼痛外,其余患者均恢复良好。按Broberg-Morrey评分标准进行综合评定,优4例,良1例,可1例,差0例,平均93.8分,患者满意度为100%。结论人工桡骨头置换术能够恢复肘关节的稳定性及活动度,是治疗桡骨头粉碎性骨折的一种良好术式。     

Radial head arthroplasty with an uncemented modular metallic radial head prosthesis: short- and mid-term results

Background  

In comminuted radial head fractures, arthroplasty is an alternative treatment to open reduction and internal fixation or radial head excision. The purpose of this study was to evaluate the short- and mid-term results after the implantation of the EVOLVE™ uncemented modular metallic radial head prosthesis.     

桡骨小头假体置换治疗成年人桡骨小头粉碎性骨折

目的 探讨采用人工桡骨头假体置换手术治疗成年人闭合性桡骨小头粉碎性骨折的早期疗效.方法 对12例桡骨小头粉碎性骨折的成年患者施行人工桡骨头假体置换手术,评价术后早期疗效.结果 患者全部得到随访,随访6～36个月,平均15个月,术后无感染病例,按HHS评分标准综合评定:优7例,良4例,一般1例,优良率91.67%.结论 成年人Mason Ⅲ型及Ⅳ型桡骨小头骨折选择人工桡骨头假体置换手术治疗后早期疗效好,远期疗效有待进一步随访和病例积累评定.     

骨水泥双极人工股骨头置换治疗高龄股骨颈骨折疗效分析

目的 探讨骨水泥双极人工股骨头置换治疗高龄股骨颈骨折的疗效.方法 自2003年6月至2008年6月收治70岁以上高龄股骨颈骨折患者69例,男23例,女46例;年龄70～98岁,平均77.8岁.骨折按照Garden分型:Ⅱ型2例,Ⅲ型25例,Ⅳ型42例,在对患者进行详细术前评估和内科处理后均行骨水泥型双极人工股骨头置换术.结果 所有患者随访6个月～5年(平均3年10个月),X线片变化情况:8例(11.6%)髋臼出现负重区轻度硬化,3例(4.3%)出现髋臼软骨磨损,未发现髋臼被磨穿者.按Harris标准进行临床效果评定:优61例,良4例,中2例,差2例,优良率94.2%.术后发生上呼吸道感染3例,泌尿系统感染2例,下肢深静脉血栓4例,心律失常1例,均经积极治疗痊愈,无死亡病例.结论 骨水泥型双极人工股骨头置换术是治疗高龄股骨颈骨折的有效方法之一,严格的术前评估和正确的手术操作是取得良好疗效的关键.     

组配型桡骨头假体置换治疗桡骨头粉碎性骨折

目的 评价采用组配型人工桡骨头假体置换治疗桡骨头严重粉碎性骨折的早期疗效和并发症.方法 2009年11月至2011年3月共收治22例桡骨头粉碎骨折患者,男16例,女6例;年龄21～62岁,平均41.5岁;左侧部9例,右侧13例.桡骨头骨折均为MasonⅢ型粉碎骨折,其中1例Ⅱ型Monteggja骨折脱位,13例合并肘部损伤“三联征”;1例合并肘关节脱位但不伴有冠状突骨折,3例合并Essex-Lospresti损伤,4例合并内侧副韧带损伤.采用Acumed组配型桡骨头假体对桡骨头进行置换,冠状突骨折采用克氏针固定,尺骨近端骨折则采用钢板螺钉固定,对2例肘部损伤“三联征”患者同时辅以铰链式外固定支架.结果 22例患者术后获6～22个月(平均12 95)随访.其中1例患者桡骨头假体位置过高,影响肘关节活动,屈肘小于90°;1例肘部损伤“三联征”患者假体位置过低,活动范围基本正常,但出现明显的肘关节侧方不稳定;1例患者术后1个月即出现严重的异位骨化并形成骨桥,最终肘关节完全僵直于屈肘70°;其余19例肘关节功能满意,平均屈肘131.5°±4.4°( 130°～140.),平均伸直受限5.4°±6.3°(0～20°),平均屈伸126.1°±7.7°(120°～140°);前臂平均旋前81.6°±6.4°( 70° ～90°),平均旋后85.6°±3.1° (80°～90°),平均旋转167.2°±8.2°(150°～ 180°),Mayo肘关节评分(MEPS)平均为(94.2±5.1)分(85 ～ 100分). 结论 组配型人工桡骨头假体可根据个体差异进行组配,是桡骨头严重粉碎性骨折的可选治疗方法之一,早期疗效较满意,但有一定的并发症,需严格把握手术适应证.