Metatarsophalangeal joint arthrodesis after failed Keller-Brandes procedure

BACKGROUND: Keller-Brandes resection arthroplasty for correction of symptomatic hallux valgus deformity can obtain early good results, but late complications, such as recurrence of the deformity and instability of the first ray, have been described. Arthrodesis of the first metatarsophalangeal, (MTP) joint can be done as a salvage procedure. The aim of this prospective study was to evaluate the clinical outcome of the arthrodesis and its effect on the biomechanics of the first ray. METHODS: Between October, 1999, and December, 2002, arthrodesis of the MTP joint was done after a failed Keller-Brandes procedure in 28 feet of 26 consecutive patients. Twenty patients (22 feet) with a minimum of 24 months followup were available for clinical and radiographic assessment. Pedobarographic measurements were obtained at latest followup in 16 patients (17 feet). RESULTS: Sixteen feet (72%) were pain-free and six feet (28%) had mild, occasional pain. The American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score increased from a preoperative 44 (range 29 to 67) points to 85 (range 73 to 90) points at longest clinical followup (average 34 months, range 23 to 48, p < 0.001). The average hallux valgus angle was corrected from 24.0 (range 7 to 47) degrees preoperatively to 16.0 (range 0 to 40) degrees postoperatively (p < 0.001). Two feet had pseudoarthroses. Biomechanically, the MTP joint arthrodesis could not fully restore the function of the hallux but produced a significant improvement, allowing a more physiologic loading pattern under the hallux and the metatarsal heads. CONCLUSIONS: First MTP joint arthrodesis after a failed Keller-Brandes procedure is a technically safe and reliable technique. It resulted in a marked reduction of pain and gain of function that produced high patient satisfaction.     

Arthrodesis of the first metatarsophalangeal joint for idiopathic hallux valgus: intermediate results

BACKGROUND: Followup studies documenting the outcome of primary metatarsophalangeal (MTP) joint arthrodesis for treatment of hallux valgus deformities are rare. The purpose of this report was to evaluate the results of first MTP joint arthrodesis as treatment for moderate and severe hallux valgus deformities over a 22-year period in a single surgeon's practice. METHODS: All living patients treated between 1979 and 2001, for moderate and severe idiopathic hallux valgus deformities with first MTP joint arthrodesis were contacted and asked to return for a followup examination. Outcomes were assessed by comparing preoperative and postoperative pain, function, and radiographic appearance. First ray mobility and ligamentous laxity also were assessed postoperatively. RESULTS: Eighteen of 21 of the first MTP joints had successfully fused with the primary procedure at an average followup of 8.2 years (range 24 to 271 months). The time to union averaged 10 (range 7 to 15) weeks. Two of the three nonunions, both in the same patient, were asymptomatic and were not revised. One required a revision to achieve fusion. The average corrections in the hallux valgus angle and 1-2 intermetatarsal (IM) angle were 21 degrees and 6 degrees, respectively, and the average postoperative dorsiflexion angle was 22 degrees. Subjective satisfaction was rated as excellent in seventeen of 21 cases (80%) and good in the remaining four (20%). There was significant reduction in postoperative pain (p < 0.001), complete resolution of lateral metatarsalgia, and the postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores averaged 84 (range 72 to 90) at final followup. Major activity restrictions after surgery were uncommon, and all patients were able to wear conventional or comfort shoes. Interphalangeal (IP) joint arthritis progressed in seven of 21 feet (33%), but all of these changes were mild. CONCLUSIONS: In the present study, arthrodesis of the first MTP joint for idiopathic hallux valgus resulted in a high percentage of successful results at an average followup of over 8 years.     

第1跖趾关节融合术后前足评分与足底压力的分析

[目的]分析第1跖趾关节融合术后对前足功能影响,以及对推进期足底压力的影响.[方法]15例患者共18足,行第1跖趾关节融合术后2年以上,根据AOFAS评分系统,对第1跖趾关节功能评分,并与正常对照组进行足底压力测试.测量前足底推进期的(足母)趾下、第1～5跖骨下共6处的峰值压强、峰值压力、压强-时间积、压力-时间积四个参数.[结果]融合术后AOFAS第1跖趾关节评分满意,术后组的(足母)趾下四项参数均明显小于正常人组.与时间相关的参数在(足母)趾下,以及第2、4、5跖骨头下小于正常人组,并具有明显差异.第1跖骨头下的峰值压强与峰值压力与对照组没有统计学差异.[结论]第1跖趾关节融合术后患者在推进期,前足跖骨头的足底压力分布与正常人基本相同.术后前足功能改善.术后(足母)趾下压力减少,但是对前足压力分布没有影响.     

类风湿性关节炎前足畸形重建手术的近期疗效

目的探讨类风湿性关节炎前足畸形的手术治疗方法及近期疗效。方法 2007年1月-2009年8月,采用第1跖趾关节融合术联合第2～5跖趾关节成形术治疗7例类风湿性关节炎前足畸形女性患者。年龄56～71岁,平均62岁。病程5～30年,平均16年。患者均表现为双足外翻,第2～5趾合并锤状趾或槌状趾畸形,其中5足合并第2跖趾关节半脱位。根据美国矫形足踝协会(AOFAS)改良标准评分为(36.9±6.4)分。术前负重位X线片测量,第1跖趾关节外翻角度(46±5)°,第1、2跖骨间夹角(12±2)°。结果术后切口均Ⅰ期愈合。术后3～4个月X线片复查示第1跖趾关节达骨性融合。7例均获随访,随访时间2～4年,平均2.9年。患者跛行步态均较术前明显改善,行走时足部疼痛明显缓解。术后3个月X线片测量第1跖趾关节外翻角度为(17±4)°,第1、2跖骨间夹角为(11±2)°,与术前比较差异均有统计学意义(P<0.05)。术后2年根据AOFAS改良标准评分为(85.3±5.1)分,与术前比较差异有统计学意义(t=4.501,P=0.001)。1例于术后4年前足转移性跖骨痛复发,继续随访中未作特殊处理。结论第1跖趾关节融合术联合第2～5跖趾关节成形术治疗类风湿性关节炎前足畸形,可获得较好外翻矫形,重塑前足负重面,有效缓解行走时疼痛。     

Rheumatoid forefoot reconstruction: 1st metatarsophalangeal fusion and excision arthroplasty of lesser metatarsal heads

This is a retrospective review of 66 feet (mean follow-up of 3 years) in 43 patients with painful severe rheumatoid forefoot deformities. All were treated by arthrodesis of the first metatarsophalangeal (MTP) joint through a dorsomedial incision and excision of the lesser metatarsal heads through a separate plantar approach. The mean post-operative AOFAS scores were 65.94 (range: 32 to 82). The mean post-operative Foot Function Index (FFI) was 0.47 (range: 0.23 to 0.63). Eighty five percent (57/67 feet) reported excellent or good pain relief, improved cosmetic appearance, and improved footwear comfort. The mean hallux valgus angles improved from 39 degrees to 16 degrees and the intermetatarsal angle from 16 degrees to 8 degrees. Five feet had nonunion of the 1st MTP joint arthrodesis. There were five re-operations for non-union of the 1st MTP joint arthrodesis. The success of the operation as evidenced by this study depends upon attention to metatarsal length harmonisation, stabilisation of the 1st MTP joint and thereby even distribution of loading of the forefoot. The poor results in this study were as a result of a failure to secure the stability of the 1st MTP joint.     

Mid-term results of Scarf osteotomy in hallux valgus

We performed a retrospective study on 178 Scarf osteotomies with a mean follow-up of 44.9 months (range 15–83 months). Clinical rating was based on the forefoot score of the American Orthopaedic Foot and Ankle Society (AOFAS). Weight bearing X-rays were used to perform angular measurements and assess the first metatarsophalangeal joint (MTP 1). At follow-up the mean AOFAS score had improved significantly (p < 0.001), but only 55% of the feet showed a perfect realignment of the first ray. Patients with a hallux valgus angle exceeding 30° and pre-existing degenerative changes at the MTP 1 joint displayed inferior clinical results (p < 0.05). Nearly 20% of the patients suffered from pain at the MTP 1 joint. This was clearly attributed to an onset or worsening of distinct radiographic signs of arthritis (p < 0.05) resulting in painfully decreased joint motion. Comparing radiographic appearance three months postoperatively and at follow-up, we found that radiographic criteria (hallux valgus, first intermetatarsal angle, hallux valgus interphalangeus, MTP 1 joint congruency, arthritic lesions at MTP 1) worsened with time.     

Arthrodesis procedures for salvage of the hallux metatarsophalangeal joint

First metatarsophalangeal (MTP) fusion has been recommended as a means to salvage various great toe deformities. These deformities include failed hallux valgus procedures, failed silicon implants, previous infection, rheumatoid arthritis, post-traumatic conditions, hallux rigidus, severe hallux valgus deformities, and neuromuscular disorders. A variety of complications, such as hallux varus, first MTP joint instability, infection, recurrent hallux valgus, and avascular necrosis of the first metatarsal head can develop from hallux valgus deformity treatment procedures.     

Rheumatoid Forefoot Reconstruction in Nonrheumatic Patients: Lesser Metatarsal Head Resection versus Osteotomy

In the literature, first metatarsophalangeal joint arthrodesis with lesser metatarsal head resection seems to be a reliable procedure in rheumatoid foot deformity. Maybe this procedure could be proposed in nonrheumatoid severe forefoot deformity (hallux valgus angle >40° and lesser metatarsophalangeal dislocation). The aim of this study was to compare radiological and clinical outcomes between lesser metatarsal head resection and lesser metatarsal head osteotomy in nonrheumatoid patients. Thirty-nine patients (56 feet) suffering from well-defined nonrheumatoid severe forefoot deformity were retrospectively enrolled in our institution between 2009 and 2015. Metatarsal head resection and metatarsal head osteotomy represented 13 patients (20 feet) and 26 patients (36 feet), respectively. In this observational study, a rheumatoid population (21 patients) was included as the control. The clinical outcome measures consisted of American Orthopaedic Foot and Ankle Society score, Foot and Ankle Ability Measurement, and Short Form-36. The radiological outcomes were: intermetatarsal angle, hallux valgus angle, and metatarsophalangeal alignment. Mean follow-up was 24 months. Satisfaction rate was, respectively, 92% for resection, 91% for osteotomy procedure, and 80% for surgery in rheumatoid patients. Short Form-36 global score was, respectively, 80.7 (52.5-96.4), 76 (57.7-93), and 68.3 (22.6-86). No functional outcome difference was found between resection and osteotomy procedures, except that the metatarsal head resection group had poorer results in sports activities than the osteotomy group. Complications were similar between osteotomy and resection (p > .05). The radiological outcomes were improved significantly from preoperative to postoperative. First metatarsophalangeal joint arthrodesis with lesser metatarsal head resection in nonrheumatoid severe forefoot deformity might be a good therapeutic option.     

Distal soft tissue procedure and proximal metatarsal osteotomy in hallux valgus

The results of a distal soft tissue procedure and a proximal metatarsal osteotomy in patients with symptomatic hallux valgus deformity were reviewed. The series consisted of 33 patients (47 feet; mean age of patients, 44 years). The average followup period was 48 months. At followup, 41 feet (29 patients, 85%) were free from pain at the first metatarsophalangeal joint. In six feet (four patients), the pain was improved but persisted. The mean hallux valgus angle was 38 degrees before surgery and 13.8 degrees after surgery. The mean intermetatarsal angle was 17.7 degrees before surgery and 7 degrees after surgery. The postoperative hallux valgus angle and intermetatarsal angle in patients who had pain at the first metatarsophalangeal joint after surgery were greater than those in patients without pain after surgery. This procedure corrects the hallux valgus deformity and relieves the symptoms, but careful attention should be paid to the surgical technique to obtain consistent and satisfactory results.     

Result of arthrodesis of the hallux metatarsophalangeal joint using bone graft for restoration of length

We treated 24 patients (18 women, six men; average age, 46.4 years; (range, 28 to 66 years) with fusion of the hallux metatarsophalangeal (MTP) joint using bone graft for the restoration of the length of the first ray. This procedure was performed after bone loss subsequent to previous surgeries for the correction of hallux valgus and hallux rigidus with: silastic arthroplasty (11), bunionectomy and distal metatarsal osteotomy (six), Keller resection arthroplasty (five), and total joint replacement (two). The indication for performing the arthrodesis with bone graft was a short first metatarsal, and associated metatarsalgia of the lesser metatarsals in addition to a painful MTP joint with or without deformity. This bone loss was associated with avascular necrosis of the first metatarsal (nine patients) and with osteomyelitis (seven patients). Of the 24 patients, 14 underwent additional concurrent surgery for correction of hammer toes (10), excision of a Morton's neuroma (two), and lesser metatarsal osteotomy (two). All patients were examined clinically and radiographically at a mean interval of 62.7 months after surgery (range, 26 to 108 months). The patients were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) hallux and MTP 100-point outcome scale. Arthrodesis occurred in 19/24 patients (79.1%) at a mean of 13.3 weeks (range, 11 to 16 weeks), and the first ray was lengthened by a mean of 13 mm (range, 0 to 29 mm). Of the five nonunions, two were asymptomatic, and three were subsequently revised successfully, with arthrodesis occurring at a mean of 10.7 weeks. Complications included one deep infection requiring intravenous antibiotics for treatment of osteomyelitis and two minor superficial wound infections. The mean AOFAS score improved from 39 points (range, 22 to 60 points) to 79 points (range, 64 to 90 points). All patients were satisfied with the final outcome of treatment and stated that they would undergo the surgical procedure again. We concluded that arthrodesis of the hallux MTP joint with bone graft to restore bone loss and length of the first ray may be a worthwhile procedure despite the technical difficulty and the high rate of nonunion.     

外翻术后再手术的原因分析及处理对策

 目的 探讨外翻术后再手术的原因及临床处理对策。方法 回顾性分析2005年12月至2011年12月外翻术后再手术的23例患者完整资料,男 3例,女20例;年龄28～85岁,平均63.1岁。再手术时间为初次手术后6～96个月,平均27.6个月。分析23例患者外翻术后再手术原因,根据患者临床症状、体征及X线片所示选择再手术方式。结果 23例外翻患者术后再手术原因包括：复发5例,内翻2例,转移性跖痛5例,内固定松动7例,内固定断裂4例。再手术方式包括：跖楔关节融合(3例),基底截骨再次行Akin截骨(1例),基底截骨加跖趾关节融合(1例),跖趾关节融合(2例),改良Weil截骨(5例),去除内固定(11例)。术后随访时间6～36个月,平均16.5个月。美国足踝外科协会(American Orthopaedic Foot and Ankle Society,AOFAS)趾、跖趾、趾间关节评分从初次术后(65.3±7.5)分改善到再次术后(89.2±8.9)分;术后患者主观满意度评价,优17例,良4例,可2例,优良率91.3%(21/23)。结论外翻术后再手术原因较多,包括复发、内翻、转移性跖痛、内固定松动、断裂等。再手术时需仔细分析患者临床症状、体征及X线检查结果选择个性化方案进行治疗。     

Intermetatarsal angle after first metatarsophalangeal joint arthrodesis for hallux valgus

BACKGROUND: First metatarsophalangeal (MTP) joint arthrodesis is commonly done for hallux valgus with an arthritic joint. In patients with a wide preoperative first intermetatarsal (IM) angle an important question is whether the metatarsus varus will be corrected by the first MTP joint fusion alone or whether an additional basal osteotomy is necessary. METHODS: The charts and radiographs of 20 patients who had arthrodesis of the first MTP joint were retrospectively reviewed. All 20 patients were female with a mean age of 54.2 (range 42 to 78) years. Either a Hallu-S plate (Integra Life Sciences, Nudeal, France) or two crossed screws were used to stabilize the arthrodesis. The IM angles were measured independently by two individuals on weightbearing preoperative, 6-week postoperative, and final followup films. The final followup radiographs were taken at an average of 13.7 (range 6 to 30) months after surgery. A Student t-test was used to evaluate the changes in the IM angle and interobserver variations. RESULTS: The mean preoperative IM angle was 16.65 (range 12 to 26) degrees. The mean postoperative IM angle was 10.35 (range 6 to 15) degrees. The mean IM angle at final followup was 8.67 (range 5 to 12) degrees. The mean change between preoperative IM angle and IM angle at final followup was 8.22 (range 4 to 14) degrees. This change of the IM angle was statistically significant (p < 0.0001). CONCLUSIONS: These results indicate that in patients with severe hallux valgus and first MTP joint degeneration arthrodesis can significantly correct the IM angle without the addition of a basal osteotomy.     

Joint preserving surgery for rheumatoid forefoot deformities improves pain and corrects deformity at midterm follow-up

BackgroundRheumatoid arthritis is a chronic autoimmune disorder that commonly affects the metatarsophalangeal (MTP) joints. Conventional surgical treatment involves joint-sacrificing surgery to relieve pain and correct deformity.ObjectivesWe retrospectively reviewed 49 patients with rheumatoid forefoot deformities who underwent 66 joint preserving procedures with Scarf osteotomy of the first metatarsal and Weil's shortening osteotomy of the lesser metatarsals.MethodThere were 5 males and 44 females with mean age 56.1 years and mean follow-up 51 months. All patients were evaluated clinically and radiologically with hallux valgus angle (HVA) and inter-metatarsal angle (IMA).ResultsMean AOFAS score improved from 39.8 preoperatively to 88.7 at final follow-up. Subjectively patients reported their outcome as excellent in 49 feet (74%), good in 9 feet, fair in 7 feet and poor in 1 foot. Five feet had residual stiffness and 11 residual pain. Mean HVA and IMA decreased from 32° to 14° and from 15° to 11° respectively.ConclusionIn intermediate to severe stages of the disease, joint preserving surgery by Scarf osteotomy of the first MTP joint and Weil osteotomy of the lesser metatarsals may be performed as an alternative to joint-sacrificing procedures and should be considered as a complement to the various surgical treatments of the rheumatoid forefoot.     

Arthrodesis compared to Mayo resection of the first metatarsophalangeal joint in total rheumatoid forefoot reconstruction

BACKGROUND: Painful forefoot deformity from rheumatoid arthritis can be treated with resection of the lesser metatarsal heads combined with either resection or arthrodesis of the first metatarsophalangeal (MTP) joint. METHODS: In a prospective, randomized study we compared arthrodesis of first MTP joint with Mayo resection as part of total forefoot reconstruction in patients with painful forefoot deformity from rheumatoid arthritis. The lesser metatarsal heads were resected and extensor tenotomy was done in all patients. Thirty-one patients were randomized to either the arthrodesis or resection group. RESULTS: After a mean followup of 36 (26 to 52) months, the median subjective satisfaction score was 96 points out of 100 in the resection group and 92 points in the arthrodesis group. Significant improvements in pain, handicap, and activity according to Foot Function Index (FFI) were found in both groups (p <0.001 except for handicap in resection group and activity in fusion group were p=0.02). There were no statistically significant differences between the groups in these measures, nor in the patients' willingness to have the procedure again. There were no recurrences of prominences or tenderness under the forefoot in either group and no recurrence of severe hallux valgus in the resection group. The arthrodeses healed in 93%. There was no higher risk for clinically relevant IP joint symptoms after arthrodesis. The operating time was significantly longer in the arthrodesis group but this was not linked to a higher wound infection rate. CONCLUSION: These results indicate that Mayo resection may still be a good choice for the first MTP joint in total forefoot reconstruction in patients with rheumatoid arthritis.     

First metatarsophalangeal arthrodesis: a clinical,pedobarographic and gait analysis study

This study investigated the results of first metatarsophalangeal (MTP) arthrodesis in terms of clinical outcome measures, plantar pressure distribution, and gait patterns. Ten feet in nine patients with severe hallux rigidus (HR) who underwent first MTP arthrodesis were studied. The preoperative evaluation included a subjective questionnaire, physical exam, AOFAS hallux score, radiographs and dynamic pedobarography (EMED). At follow-up (average 34 months) these were repeated, and gait analysis studies were obtained. Patients showed significant clinical improvement based on the subjective criteria. The mean AOFAS score improved from 38 preoperatively to 90 postoperatively. Postoperative EMED analysis showed restoration of the weightbearing function of the first ray, with greater maximum force carried by the distal hallux at toe-off. Kinematic and kinetic gait analysis from each patient's operative limb were compared to the unaffected contralateral limb and to age- and sex-matched healthy subjects. The kinematic data indicated a significantly shorter step length with some loss in ankle plantar flexion at toe-off on the fused side. The kinetic data indicated a reduction in both ankle torque and ankle power at push-off. Clinical results indicated effective pain relief and a high level of patient satisfaction, consistent with previous reports in patients with symptomatic Hallux Rigidus.     

Soft-tissue arthroplasty for hallux rigidus

Seven patients (seven feet) were evaluated at an average follow-up of 42 months following soft-tissue interposition arthroplasty of the hallux metatarsophalangeal (MTP) joint for severe hallux rigidus. The technique involved reaming of the base of the proximal phalanx and metatarsal head to decompress the first MTP joint and placement of a soft-tissue tendon bundle as a biologic spacer. Six of seven patients had bilateral disease, and a positive family history of hallux rigidus. At final follow-up, all seven patients rated their result as good or excellent, the level of pain was substantially reduced, and the mean AOFAS score substantially improved from 46 to 86 points. Mild metatarsalgia was noted by four patients and characterized by mild plantar callosities in these cases. The mean MTP dorsiflexion improved from 9 degrees to 34 degrees and patients demonstrated good to excellent plantarflexion strength on manual muscle testing and with toe rise. Physical examination of the involved feet demonstrated no evidence of pes planus, metatarsus primus elevatus, Achilles tendon contracture, or metatarsocuneiform joint hypermobility in any of the seven. The technique of soft-tissue interposition arthroplasty as described gave excellent pain relief and reliable function of the hallux, and is an alternative treatment to MTP arthrodesis in select cases of severe hallux rigidus.     

The management of the painful first metatarsophalangeal joint in the older patient. Arthrodesis or Keller's arthroplasty?

We report a prospective randomised trial comparing Keller's arthroplasty and arthrodesis of the first metatarsophalangeal joint for the management of symptomatic hallux valgus and hallux rigidus in the older patient. In 81 patients (110 feet), with a minimum of two years follow-up, both procedures gave a similar degree of patient satisfaction and symptom relief. The incidence of metatarsalgia was also similar. As there were no obvious advantages to arthrodesis, and since six out of 50 arthrodesed toes required revision, we suggest that Keller's arthroplasty is the better operation in these patients.     

Arthrodesis of the first metatarsophalangeal joint

Arthrodesis has emerged as the primary salvage procedure for severe osteoarthritis of the first metatarsophalangeal (MTP) joint. Forty-three patients underwent arthrodesis of the first MTP joint with stabilization provided by either 2 crossed lag-screws or a dorsal plate and screws. First MTP joint arthrodesis was the primary procedure for 46 of the 54 treated feet. Joint surfaces were shaped into a ball-and-socket configuration to augment joint surface contact and facilitate alignment for arthrodesis. Postoperative care involved using a compressive bandage, a surgical shoe, and a cane, crutches, or a walker. Partial weight-bearing was allowed immediately after surgery. Few casts were used postoperatively. At a mean of 21.7 months (median, 13.5 months), 34 of the 43 patients completed a brief telephone survey about surgical outcomes. Radiographic measurements of intermetatarsal, hallux valgus, inclination, and dorsiflexion angles were made preoperatively and postoperatively. Mean time to fusion was 7.3 weeks; arthrodesis was successful for 50 of 52 feet (radiographs were missing for 2 of the 54 feet treated). Internal fixation devices were removed from 5 feet. Thirty (88.2%) of the 34 patients rated their result as excellent or good; the other 4 (11.8%) rated their result as poor.     

Hemiarthroplasty in the treatment of hallux rigidus

BACKGROUND: Osteoarthritis of the first metatarsophalangeal (MTP) joint is a painful, disabling condition. It can interfere with the ability to run and even walk without pain. An implant of cobalt-chrome steel alloy to replace the base of the proximal phalanx is one solution. The purpose of this study is to review our results with one of these implants. MATERIALS AND METHODS: A series of 23 cases of hemiarthroplasty for the treatment of hallux rigidus from June 2000 to October 2001 has been evaluated using the AOFAS rating system, and the results are presented. RESULTS: The average preoperative AOFAS score was 57 (range, 39 to 80). The AOFAS score after hemiarthroplasty was 88 (range, 75 to 100) at last followup (34 to 72 months). There were no perioperative complications except for a small hematoma. Only one patient has required further surgery after 3 years for worsening of a preexisting tendency to hallux valgus. CONCLUSION: A hemiarthroplasty retained, in most cases, joint mobility, strength, and alignment while relieving pain. There was no evidence, at last followup, of component loosening or osteolysis.