Hip Arthroscopy After Total Hip Arthroplasty Is Rare (0.04%) and May be Contralateral

Abstract

Purpose

To determine the patient demographics and incidence of hip arthroscopy after total hip arthroplasty using the PearlDiver database.

Methods

This is a retrospective study of patients undergoing total hip arthroplasty and arthroscopic hip surgery. The PearlDiver Claims Database was queried using Current Procedural Terminology (CPT) codes for records from 2010 to 2021. Inclusion criteria were presence of a hip arthroplasty CPT code, followed by a hip arthroscopy CPT code. Additional data collected included age, sex, and time between surgeries. A subanalysis for International Classification of Diseases (ICD), Ninth (-9) and Tenth (-10) Revision, codes was completed to estimate association with iliopsoas tendinitis.

Results

Query of the database showed that 314 patients had a hip arthroscopy code after a hip arthroplasty code. In total, 0.04% of patients who underwent arthroplasty subsequently underwent arthroscopy; 63.4% were female. Mean age was 58.2 ± 12.2 years at time of arthroscopy. A total of 214 (72.3%) patients had a CPT code for synovectomy, 56 (18.9%) for loose body removal, and 44 (15.3%) for diagnostic arthroscopy. The mean time from arthroplasty code to arthroscopy code was 2.5 ± 2.0 years. In total, 105 patients (33.4%) also had an ICD-10 diagnosis code for iliopsoas tendinitis, and 116 (36.9.0%) had the ICD-9 code for enthesopathy of hip.

Conclusions

In this study, we found that hip arthroscopy after hip arthroplasty is uncommon but occurs more frequently in female patients, is undertaken in a broad age range of patients, and often is associated with a diagnosis of iliopsoas or hip tendinitis.

Level of Evidence

Level IV, retrospective case series.

The rate of total hip arthroplasty (THA) is increasing and is expected to increase dramatically in the next decade.¹ The incidence of hip arthroscopy also has grown substantially.² Although the most familiar indications for hip arthroscopy are native hip femoroacetabular impingement and labral pathology,³ arthroscopy has become a powerful minimally invasive tool for the assessment and treatment of hip pain after THA.4, 5, 6

In a systematic review of 18 studies and 171 patients, Heaven et al.⁵ found that the most common indications for arthroscopy after hip arthroplasty were iliopsoas tendinopathy and “symptomatic hips with no clear diagnosis despite extensive investigation.” Additional, less-frequent indications included the evaluation and diagnosis of periprosthetic infection and presence of intra-articular loose bodies. Iliopsoas impingement as a cause of persistent groin pain after arthroplasty is likely underdiagnosed.⁷ Impingement often is attributable to variations in implant positioning such as an oversized or malpositioned acetabular component.⁸ Arthroscopic or endoscopic tenotomy is a much less-invasive surgical option than component revision and has been shown to improve outcomes.⁷

Although the indications for hip arthroscopy after arthroplasty are expanding, there is little known about the frequency of the procedure, whether it is increasing over time, and whether there are any demographic associations such as age or gender. Therefore, the purpose of this study is to was determine the patient demographics and incidence of hip arthroscopy after THA using the PearlDiver database. We hypothesized that the incidence of hip arthroscopy after THA would be low, and that it frequently would be associated with a diagnosis of iliopsoas tendinopathy.

Methods

This study was approved by the institutional review board. This is a retrospective study using Current Procedural Terminology (CPT) codes of patients undergoing THA and arthroscopic hip surgery using the PearlDiver Claims Database, which includes insurance claim records from 2010 to 2021.

The CPT codes selected as inclusion criteria in this study were 27130 (total hip arthroplasty), 27132 (conversion of prior hip surgery to total hip arthroplasty), 27134 (revision of total hip arthroplasty, both components), 27137 (revision of total hip arthroplasty, acetabular component only), 27138 (revision of total hip arthroplasty, femoral component only), 29860 (hip arthroscopy, diagnostic with or without biopsy), 29861 (hip arthroscopy, removal of loose or foreign body), and 29863 (hip arthroscopy, with synovectomy). To be included, patients must have a hip arthroplasty code (27130, 27132, 27134, 27137, 27138) and a hip arthroscopy code that occurred after the date of their hip arthroplasty. The inclusion criteria are illustrated in Table 1.

Table 1.

Inclusion Criteria

A CPT for Primary or Revision THA		A CPT for Hip Arthroscopy Occurring after THA
27130: THA		29860: Diagnostic hip arthroscopy
27132: Conversion of prior surgery to THA	AND	29861: Removal of loose/foreign body
27134: Revision of both components		29863: Hip arthroscopy, synovectomy
27137: Revision of acetabular component
27138: Revision of femoral component

Shown are CPT codes used to query the database.

CPT, Current Procedural Terminology; THA, total hip arthroplasty.

Additional data collected included age, sex, and year of surgery. The database does not allow for determination of laterality. A subanalysis was also completed to identify patients in the study who also had International Classification of Diseases, Ninth Revision (ICD-9) or International Classification of Diseases, Tenth Revision (ICD-10) codes for iliopsoas tendinitis or tendinopathy. For ICD-9, 726.5 (enthesopathy of hip) was used. For ICD-10, M17.1 (iliopsoas tendinitis) was used to extrapolate an estimate of how many arthroscopies were for iliopsoas impingement.

Microsoft Excel was used to calculate means and percentages and create graphs. Because the database provided the age of each patient in a 5-year range, and estimate of the mean was calculated by assigning each patient’s age in the middle of the 5-year range.

Results

Query of the database identified 851,206 patients with a hip arthroplasty code. Further query revealed that 314 patients had a hip arthroscopy code after a hip arthroplasty code. Expressed differently, 0.04% of patients in the database who underwent hip arthroplasty subsequently underwent hip arthroscopy. In total, 63.4% (199) of patients were female. Mean age was 56.8 ± 12 years at the time of arthroplasty and 58.2 ± 12.2 years at the time of arthroscopy. At the time of arthroscopy, age range was 30 to 79 years, and age 55 to 59 years was the most common patient age group (17% of patients). A graph depicting the age of the patients at time of arthroplasty versus the age of the patients at the time of arthroscopy may be seen in Figure 1.

Fig 1.

Bar graph depicting age at time of hip arthroplasty (blue bars) and age at time of hip arthroscopy (green bars). The x-axis represents age, and the y-axis represents number of patients.

The mean time elapsed between arthroplasty code and arthroscopy code was 2.5 ± 2.0 years. A graph depicting when (organized by year) the arthroplasty and arthroscopy surgeries took place may be seen in Figure 2. In total, 81.8% of arthroscopies were performed after a primary THA and 12.5% after a revision arthroplasty (Fig 3). 214 (68.2%) patients had a CPT code for synovectomy, 56 (17.8%) for loose body removal, and 44 (14.0%) for diagnostic arthroscopy (Fig 4). Of those who underwent arthroscopy after arthroplasty, 105 (33.4%) also had an ICD-10 diagnosis code for iliopsoas tendinitis and 116 (36.9.0%) had the ICD-9 code for enthesopathy of hip.

Fig 2.

Line graph depicting the number of patients undergoing arthroplasty (blue line) and arthroscopy (green line) by year. The x-axis represents years, and the y-axis represents number of patients.

Fig 3.

A pie graph representing the percentage of patients with each hip arthroplasty code before their hip arthroscopy. (THA, total hip arthroplasty.)

Fig 4.

A pie graph representing the percentage of patients with each hip arthroscopy code.

Discussion

In this study, using the PearlDiver database, we found that the incidence of patients undergoing a THA followed by a hip arthroscopy between 2010 and 2021 was low, at 0.04%. Analysis of the demographics found that arthroscopy after arthroplasty occurs more frequently in female patients (68%), is undertaken in a broad age range of patients (30-79 years), and is often associated with a diagnosis of iliopsoas or hip tendinitis (70% of patients).

Before being used as a tool after hip arthroplasty, arthroscopy was used after total knee arthroplasty. Indications include diagnosis and treatment of prosthetic joint infection,⁹ arthrofibrosis,¹⁰ patellar clunk or soft-tissue impingement,¹¹ and loose bodies including cement fragments.¹² As skills in hip arthroscopy have increased, surgeons have used this minimally invasive approach to treat a variety of conditions after THA. In their systematic review of 18 studies and 171 patients undergoing arthroscopy after THA, Heaven et al.⁵ found that the indication for arthroscopy was iliopsoas tendinopathy in 36% of patients, periprosthetic infection in 6% of patients, intra-articular loose body in 3% of patients, and “symptomatic hips with no clear diagnosis despite extensive investigation” in 26% of patients. Additional applications of arthroscopy include diagnosis of component loosening, synovitis, and capsular scarring with adhesions.¹³

All patients with hip pain after THA should undergo extensive workup to identify an underlying cause for their pain. Many explanations for a painful THA such as periprosthetic infection, component loosening, and instability are often not possible to treat arthroscopically.^14,15 Iliopsoas impingement accounts for pain after hip arthroplasty in approximately 4% of cases.⁷ It is thought to be related to an oversized or malpositioned acetabular component.⁸ It is difficult to determine the exact indication for hip arthroscopy from the database because of limitations in hip arthroscopy CPT coding. Furthermore, there is no specific CPT code for arthroscopic iliopsoas release. Despite this limitation, we were able to investigate the presence of ICD-9 and -10 diagnosis codes for iliopsoas tendinitis. In our study, the diagnosis of iliopsoas tendinopathy was present in up to 70% of patients, suggesting that many of the arthroscopies were performed for iliopsoas lengthening/tenotomy. Arthroscopic lengthening/tenotomy is not the only treatment option for iliopsoas impingement. However, it is significantly less invasive than open lengthening or revision of the acetabular component. Shapira et al.¹⁶ showed that acetabular component revision has more complications than arthroscopic iliopsoas lengthening. Outcome studies have showed promising results; Viamont-Guerra et al.¹⁷ found in their study of 48 patients that 76% experienced clinically meaningful improvements in Modified Harris Hip Score. Guicherd et al.¹⁸ reported in their study of 64 patients that 92% experienced pain alleviation postoperatively. The most important factor in treating iliopsoas impingement is establishing the correct diagnosis.¹⁹ Outcomes measures were not available in the PearlDiver database and therefore could not be included in the results of this study. For patients in whom iliopsoas impingement is suspected, a workup to rule out other causes and diagnostic interventions to confirm the diagnosis (such as iliopsoas cortisone injection) should be pursued before considering arthroscopic intervention.

Limitations

There are several limitations to this study. A major limitation of this study is that laterality could not be determined from the database. This introduces the possibility that some arthroplasty patients may have undergone subsequent arthroscopy on the contralateral hip. The true incidence of hip arthroscopy after arthroplasty in this time period is likely underestimated, because patients with their arthroplasty CPT code occurring before 2010 are not able to be captured. In addition, there is no specific CPT code for arthroscopic iliopsoas lengthening or tenotomy, so it is difficult to determine what was performed at the time of surgery. Surgeons may use a variety of CPT codes to bill for this procedure, including 29863 (synovectomy) and 27999 (unlisted arthroscopic procedure). 27999 was not tracked in this study because it is not specific to the hip and can be used in any joint. Finally, this study is retrospective and does not include outcomes data.

Conclusions

In this study, we found that hip arthroscopy after hip arthroplasty is uncommon but occurs more frequently in female patients, is undertaken in a broad age range of patients, and is often associated with a diagnosis of iliopsoas or hip tendinitis.

Disclosures

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: M.B.B. reports consulting or advisory, funding grants, and speaking and lecture fees from Arthrex and Smith & Nephew; funding grants from Stryker Orthopaedics; consulting or advisory and speaking and lecture fees from Vericel; board membership, American Association of Orthopaedic Surgeons, Arthroscopy Association of North America, International Congress for Joint Reconstruction, and Hip Society. C.A.O. declares that she has no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.