Improvements in instrumentation, safe joint distraction techniques, and surgical expertise have overcome the technical challenges that previously limited hip joint access through arthroscopy. The ability to directly diagnose and treat hip abnormalities with minimally invasive techniques continues to evolve. Indications for hip arthroscopy in the native hip have included management of labral tears and chondral lesions, removal of loose or foreign bodies, subtotal synovectomy, and synovial biopsy and pyarthrosis [12
]. The role of arthroscopy in the workup and treatment of problems related to previous hip arthroplasty is less clear. Specifically, the value of arthroscopy in evaluating the persistently painful hip arthroplasty remains unknown.
Limitations of this study include the absence of standardized preoperative and postoperative outcomes scores. However, in this group of patients with somewhat unusual clinical problems, it would be difficult to determine what outcome instrument would best capture their hip status. Furthermore, although this series represents an inclusive group of patients who underwent arthroscopy postarthroplasty, we did not define strict inclusion criteria in advance.
A number of case reports [9
] and small case series [4
] have described hip arthroscopy after previous arthroplasty. Hyman et al. [4
] reported eight patients treated with arthroscopic irrigation and débridement for confirmed late periprosthetic infection. They noted no recurrence of infection and no progressive radiographic loosening at a mean followup of 70 months [4
]. Open arthrotomy and débridement has remained our standard treatment for the acutely infected hip arthroplasty. However, we successfully treated one patient who was not a candidate for open arthrotomy using arthroscopy. In a second patient with suspected joint infection, the diagnosis was confirmed and treated through arthroscopy.
The removal of foreign bodies and entrapped cement using arthroscopic techniques has been previously reported after hip arthroplasty [9
]. In these cases, dislocations of hip implants in either the perioperative period or later resulted in entrapment of the implanted drain or fragmented cement debris, preventing successful closed reduction. Hip arthroscopy was used to clear the interposed material and enable closed reduction of the hip prosthesis. None of the patients in this series were treated for entrapped debris postdislocation; however, we were able to successfully remove migrated hardware using arthroscopic techniques in three cases.
We identified previously unrecognized component-related problems in two patients (metal corrosion in one patient and acetabular loosening in another). Both patients were subsequently treated with revision arthroplasty. In a previous report [3
], arthroscopy was used to assess acetabular cup loosening in a patient with clinical and radiographic signs of massive polyethylene wear 3 years after THA. The polyethylene was broken into three pieces. Khanduja and Villar [6
] recently described the use of hip arthroscopy to diagnose a loose acetabular component in a patient who presented with persistent pain after resurfacing hip arthroplasty and had a negative preoperative workup for infection and loosening.
Three of the four patients in this study with impinging scar tissue experienced complete pain relief after débridement; an additional two patients out of four with nonimpinging scar tissue plus synovitis had complete resolution of their symptoms. One patient with adhesions and capsular scarring without impingement or synovitis had complete resolution of symptoms after arthroscopic débridement (Fig. ). Although this has not been previously documented in arthroscopy post-THA, the literature supports arthroscopy after TKA for débridement of fibrous scar tissue causing painful, limited motion, patella clunk, and tethered patella syndrome [1
]. It is important to note, however, arthroscopy was least successful in this subgroup of patients with only five of nine patients achieving complete pain relief.
Case 15. Impinging soft tissue is visible during arthroscopic débridement.
Most problems after hip arthroplasty can be diagnosed by clinical examination (leg-length discrepancy, abductor weakness, etc.), plain radiography (component loosening, malposition, trochanteric nonunion, etc.), or special studies such as bone scan or aspiration arthrogram (subtle loosening or sepsis). Often, newer imaging modalities such as CT or MRI are of limited utility in these cases due to metal artifact that limits the ability to visualize peri- and intraarticular structures. In cases in which unexplained symptoms persist despite negative diagnostic evaluation, surgeons have been cautious to proceed to diagnostic open arthrotomy as a result of the prolonged recovery and associated risks of infection, instability, deep venous thrombosis, pulmonary embolism, muscle weakness, and nerve injury. In this situation, arthroscopy may be a useful diagnostic, and sometimes therapeutic, tool. The work up for patients in this series consisted of plain radiographs, aspiration arthrogram, and blood work consisting of complete blood count with differential, C-reactive protein, and sedimentation rate. Metal-reduction CT and MRI were not available for most of the patients in this study. One of the most recent patients did have a negative aspiration arthrogram spiral CT. Two of the patients with persistent groin pain had no relief from injecting the psoas sheath under ultrasound guidance with a cortisone derivative and long-lasting analgesic. Two patients had intraarticular analgesic injections without relief and four patients were referred for spine evaluation that failed to indicate lumbar pathology as a source of pain. In this series, arthroscopy effectively treated or directly led to effective treatment in eight of 12 cases presenting as diagnostic dilemmas. Arthroscopy also served as an effective therapeutic alternative in four cases with known postarthroplasty problems. Arthroscopy allowed for direct inspection of the joint and implants without the morbidity and risks associated with open arthrotomy. All cases were performed on an outpatient basis and the recovery period was substantially shorter than after open arthrotomy. Our indications for arthroscopy after THA continue to evolve. We are more inclined to perform arthroscopy in patients with identifiable loose bodies or signs and symptoms of impingement. Further prospective, controlled studies are needed to further define the role of arthroscopy in evaluating the painful hip arthroplasty.