Marc Darrow, MD, JD.
Many people contact me with problems of a confusion in their hip or low back diagnosis. They have confusion because they have had low back pain coupled with hip pain and after a long time trying to determine what was the cause of their pain, their doctors came back with a diagnosis of Femoroacetabular Impingement (FAI) or more simply a hip impingement. They were then told that they have a condition where the ball and the socket of the hip were rubbing against each other in a non-anatomically correct way and that this was causing friction in the hip joint. This friction can also cause a sensation of low back pain.
Usually people who contact my office will have a diagnosis of their hip impingement broken down into one of three types.
They have a:
- A cam impingement. This is boney formations or spurs at the base of the ball or femoral head. If the bone spur is large enough it can prevent full range of motion in the hip and prevent the ball from rotating within the socket. The abnormal movement between the ball and socket can also cause an accelerated breakdown of the hip cartilage.
- A pincer impingement. Here instead of bone spurs at the base of the femoral head, the bones spurs form at the edge of the socket or acetabulum. This can also cause friction in the socket, accelerated cartilage damage, loss of range of motion and tearing or impingement of the hip labrum.
- Both. A situation of combined cam and pincer impingement.
In Femoroacetabular Impingement Syndrome bone spurs can develop around the femoral head (the ball) and/or along the acetabulum (the socket). The bone spurs prevent the normal range of motion and contact between the ball and socket. This is a degenerative disorder and over the course of time Femoroacetabular Impingement Syndrome can cause degenerative wear and tear of the hip labrum and cartilage resulting in hip osteoarthritis.
A November 2023 paper (1) offers to “serve as a guide for non-operative physicians in the management of femoroacetabular impingement syndrome and provide an algorithm as to when to refer patients for potential surgical management.” The paper suggests: “Supervised physical therapy programs that focus on active strengthening and core strengthening are more effective than unsupervised, passive, and non-core-focused programs. There is promising evidence for the use of intra-articular hyaluronic acid and PRP as adjunct treatment options. Recent systematic reviews and meta-analyses have found that in young active patients, hip arthroscopy demonstrates improved short-term outcomes over physical therapy. . . .Evidence is currently lacking to support the use of initial arthroscopy for Femoroacetabular Impingement Syndrome to prevent later development of hip osteoarthritis.”
Who would femoroacetabular impingement syndrome surgery benefit more?
In a December 2023 doctors (2) reviewed the patients charts of patients five years after their hip arthroscopic surgery for femoroacetabular impingement syndrome (FAI). The goal of this medical review was to help determine pre-surgery factors that may make the surgery more successful. The main factor was to assess the patient’s severity of symptoms prior to the hip procedure.
Using patient reported Minimal Clinically Important Difference scores (the minimal amount of symptom relief that the patients considered the procedure to be successful) and Patient Acceptable Symptomatic State scores (the current severity of symptoms of which the patients considered the surgery a success) the patient reviews of the 105 patients revealed that patients with higher function before surgery would have better outcomes than patients with lower functional abilities prior to the surgery.
- The preoperative higher functional group achieved higher Minimal Clinically Important Difference (77% vs. 57%) versus lower functional group.
- The preoperative higher functional group achieved higher Patient Acceptable Symptomatic State (66% vs. 45%) versus lower functional group.
The researchers concluded: “Subjects with high preoperative function are likely to have increased longevity of the index procedure while maintaining excellent Patient Acceptable Symptomatic State and Minimal Clinically Important Difference rates mid-term as opposed to those with low preoperative function.”
A December 2023 study (3) compared the surgical outcomes in patients with pre-surgery back problems against those patients without low back pathology having primary hip arthroscopy for the treatment of femoroacetabular impingement (FAI) syndrome. In reviewing data from fourteen published studies which included 750 hips with low-back problems and FAI (hip-spine syndrome) and 1,800 hips with only FAI (no hip-spine syndrome), the authors found, according to data, “patients undergoing primary femoroacetabular impingement hip arthroscopy with concomitant low-back pathology can expect favorable outcomes, but outcomes are superior in patients undergoing hip arthroscopy for femoroacetabular impingement alone as compared to those patients with femoroacetabular impingement and low-back pathology.
A January 2024 comparison study (4) of long-term outcomes in arthroscopic surgery for Femoroacetabular Impingement Syndrome looked to assess differences in patient reported outcomes in those who had no osteoarthritis at the time of surgery versus those with mild osteoarthritis at the time of surgery.
- Patients were divided into two groups. Tönnis grade 1 (mild hip osteoarthritis) and Tönnis grade 0 (no demonstrated osteoarthritis on imaging studies).
- Both groups demonstrated significant improvements regarding all patient reported outcomes at minimum 10 years, except for the Hip Outcome Score Activities of Daily Living subscale in the Tönnis grade 1 group.
- Patients with Tönnis grade 1 had significantly higher rates of conversion to total hip replacement compared with patients who had Tönnis grade 0 (25.8% vs 4.8%).
A December 2023 study (5) found that hip arthroscopy for femoroacetabular impingement is associated with improved sexual function and quality of life. The study collected data on those over 40 and under 40 and separated out men and women in the data analysis. Pre and six months post surgery, 2547 patients answered questions about their quality of life to include sexual activity. Following surgery, the majority of patients recorded significant increases in frequency and pleasurable sex activity. Female patients demonstrated a significantly greater improvement in their scores for sexual function from pre-operatively to 6-months and 12-months following surgery, compared to male patients. The effect of age on improvements in sexual function did not demonstrate a significant difference.
A January 2024 study (6) assessed whether surgeons should offer arthroscopic mini-open femoroacetabular osteoplasty in patients with advanced hip osteoarthritis. In this study, patients who with Tönnis Grades 2 or 3 (advanced osteoarthritis) were compared to those patients with none or mild osteoarthritis (Tönnis Grade 0 or 1). Both groups having had the mini-open femoroacetabular osteoplasty. At five years, approximately 25% of patients undergoing mini-open femoroacetabular osteoplasty with Tönnis Grade 2 or higher osteoarthritis underwent conversion to total hip replacement. Some postoperative functional scores were lower in patients with advanced arthritis than in matched patients with no or mild arthritis. (The study) “emphasized the importance of exercising caution when considering femoroacetabular osteoplasty in patients in whom advanced arthritis is already evident at the time of presentation.”
A December 2023 study (14) found that “Patients who participate in flexibility sports (examples being dance, gymnastics, yoga, cheerleading, figure skating, and martial arts) demonstrate favorable postoperative patient-reported outcomes after undergoing arthroscopy for FAIS at a minimum of 12 months. In addition, the majority of athletes were able to return to sport at a similar or higher level than pre-surgery. This supports the hypothesis that hip arthroscopy is beneficial for flexibility sports athletes hoping to return to sport. In addition, the pre- and postoperative differences in the various patient-reported outcomes signify an improvement in important metrics such as pain, quality of life, and function.”
Connecting low back pain and femoroacetabular impingement syndrome
A January 2022 paper (7) examined the prevalence of low back pain and related disability in patients with femoroacetabular impingement syndrome. In this paper the researchers wrote: “Low back pain has been associated with worse hip function for persons with femoroacetabular impingement syndrome.” The researchers then hypothesized that study participants with low back pain would be older, have higher body mass index (BMI), and report worse groin pain, longer symptom duration, and worse hip function. We hypothesized that worse low back pain-related disability and low back pain severity would be related to worse hip function.” Their findings: “Clinically significant low back pain is highly prevalent in persons with femoroacetabular impingement syndrome and is associated with worse hip function. Worse femoroacetabular impingement syndrome-related disability, but not femoroacetabular impingement syndrome severity, was strongly associated with worse hip function.
Conservative care non-surgical treatment
Most people that come into our office have been to other doctors and they, for the most part, tell us about the treatments and recommendations they have received up until this point.
- Reduce or limit activities that worsen hip pain.
- Over the counter or prescription strength Nonsteroidal anti-inflammatory medications.
- Physical therapy and exercise programs.
A November 2021 paper (8) wrote about the more or less ineffectiveness of physical therapy: “Prescribed physiotherapy, consisting of hip strengthening, hip joint manual therapy techniques, functional activity-specific retraining and education showed a small to medium effect size compared with a combination of passive modalities, stretching and advice (very low to low quality of evidence; interpretation of evidence: very uncertain, but may slightly improve outcomes). Prescribed physiotherapy was, however, inferior to hip arthroscopy (small effect size; moderate quality of evidence; interpretation of evidence: hip arthroscopy probably increases outcome slightly).”
A March 2022 study (9) suggested which people may be at risk for a failed arthroscopic procedure for Femoroacetabular Impingement Syndrome. Using a unique scoring system to reliably predict clinically meaningful improvement after hip arthroscopy for Femoroacetabular Impingement Syndrome, the researchers wrote: “Despite consistent improvements after hip arthroscopy, meaningful improvements are negatively influenced by greater Body Mass Index (BMI), back pain, chronic symptom duration, preoperative mental health, and use of hip corticosteroid injections.”
From April 2020, from the The American journal of sports medicine.(10)
“While the indications for primary hip arthroscopic surgery in treating femoroacetabular abnormalities continue to be defined, the indications and outcomes for revision hip arthroscopic surgery remain ambiguous. However, revision hip arthroscopic surgery is performed in 5% to 14% of patients after their index procedure. While patient-reported outcomes generally improve after revision procedures, the extent of their improvement is not well defined. . . ” The researchers also note that after revision hip arthroscopic surgery, studies have suggested the rates of conversion to total hip replacement ranged up to 14.3%, and the rates of further arthroscopic revision ranged also ranged to 14% of patients.
In a June 2023 paper (15) researchers looked to assess outcome data for non-surgical treatments for the management for femoroacetabular impingement (FAI) and concomitant Tönnis Grade 2 or higher osteoarthritis. They did not find any data as there were no studies that met the criteria they were looking to assess.
The researchers then went to a secondary analysis included 24 studies that reported on outcomes for non-operative interventions for FAI irrespective at any osteoarthritis level.
Here they found level I evidence supporting the effectiveness of activity modification and hip-specific physiotherapy for femoroacetabular impingement and mild osteoarthritis. Core-strengthening exercises have been shown to be among the more successful regimens. Contradictory evidence questions the efficacy of hip bracing even for short-term outcomes.
Corticosteroid injections have mostly failed in intention-to treat analyses but may be valuable in delaying the need for surgery. Reports on outcomes following hyaluronic acid injections are contradictory.
The use of PRP during Femoroacetabular Impingement surgery
A January 2021 paper (11) examined the application of biologics (injections made from cells) during arthroscopic FAI surgery. In reviewing past research the study authors wrote: “An randomized control trial examined the effects of intra-articular injection of PRP during hip arthroscopy with indication of Femoroacetabular Impingement. (A group of patients) treated with PRP intraoperatively reported lower pain scores 48 hours post-operatively and demonstrated fewer joint effusions at six-month follow-up. The study supported the use of intraoperative PRP intra-articular injections to reduce inflammation following hip arthroscopy but concluded more research should be conducted to determine long-term benefits. Similarly, another randomized control trial demonstrated decreased inflammation and ecchymosis (skin discoloration) following hip arthroscopy with intra-articular PRP injections. Despite immediate post-operative benefits, the study concluded that PRP injections did not produce significant improvements in outcomes at 1-year follow-up when comparing 20 patients who received PRP to 15 control patients without PRP intra-articular injections.
A November 2023 paper (12) reviewed the case histories of 345 patients who were recruited into their study to assess whether PRP injections into the hip capsule during arthroscopic surgery for Femoroacetabular Impingement Syndrome provided the patients with any recovery benefits. The 345 patients were divided into two groups. The great majority, 293 patients were in the group that had the during surgery PRP injection. The other 52 did not have the PRP. The results revealed “The data from this study suggest that there is no difference in outcomes with PRP injection onto the capsule after capsular closure during hip arthroscopy, despite PRP having been shown to have beneficial effects in other applications within orthopaedics. The lack of effect of the PRP in these patients may have been the result of many factors, including anti-inflammatory medications taken during the postoperative period as part of multimodal pain control, dilution of the PRP within residual arthroscopic irrigation fluid, or no true effect of capsular healing by the PRP.”
An October 2023 paper (13) reviewed 440 patient outcomes from eleven studies following PRP, hyaluronic acid, or cell based treatments during or soon after their femoroacetabular impingement syndrome surgery. The paper’s authors wrote that all 11 studies showed improvements in patient reported outcomes from baseline to most-recent follow-up. In four studies, PRP injections were given either intraoperatively or the day after surgery as a secondary treatment for labral repair.
Cell based therapies was used intraoperatively in acetabular chondral lesion repair (three studies) and labral repair (one study). When compared to a control group at most recent follow-up, three PRP groups demonstrated similar patient reported outcomes, while one PRP group exhibited worse visual analog pain scores. The four cell based therapies studies reported favorable results compared to a control group.
1 Pasculli RM, Callahan EA, Wu J, Edralin N, Berrigan WA. Non-operative management and outcomes of femoroacetabular impingement syndrome. Current Reviews in Musculoskeletal Medicine. 2023 Nov;16(11):501-13.
2 Akpinar B, Lin LJ, Bloom DA, Youm T. Preoperative Symptom Severity Predicts 5-Year Hip Arthroscopy Outcomes. Bulletin of the NYU Hospital for Joint Diseases. 2023 Oct 1;81(4):249-58.
3 Lee, M.S., Mahatme, R.J., Simington, J., Gillinov, S.M., Kim, D.N., Moran, J., Islam, W., Fong, S., Pettinelli, N., Lee, A.Y. and Jimenez, A.E., 2023. Over 50% of Studies Report Low Back Pain is Associated with Worse Outcomes After Hip Arthroscopy When Compared to a Control Group: A Systematic Review. Arthroscopy: The Journal of Arthroscopic & Related Surgery.
4 Fenn TW, Kaplan DJ, Brusalis CM, Chapman RS, Larson JH, Nho SJ. Functional outcome scores and conversion to total hip arthroplasty after hip arthroscopy for femoroacetabular impingement syndrome in patients with Tönnis grade 1 versus grade 0 arthritis: a propensity-matched study at minimum 10-year follow-up. The American Journal of Sports Medicine. 2024 Jan;52(1):34-44.
5 Smith C, Nero L, Holleyman R, Khanduja V, Malviya A. Hip arthroscopy for femoroacetabular impingement is associated with improved sexual function and quality of life. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2023 Dec 27.
6 Abdelaal MS, Sutton RM, Sherman MB, Parvizi J. Mini-open Femoroacetabular Osteoplasty in Patients With Tönnis Grade 2 or Higher Osteoarthritis is Associated With a Higher Risk of Subsequent Conversion to THA. Clinical Orthopaedics and Related Research®. 2022 May 10:10-97.
7 Brown‐Taylor L, Bordner H, Glaws K, Vasileff WK, Walrod B, Di Stasi S. Prevalence of low back pain and related disability in patients with femoroacetabular impingement syndrome. PM&R. 2021 Feb 14.
8 Ishøi L, Nielsen MF, Krommes K, Husted RS, Hölmich P, Pedersen LL, Thorborg K. Femoroacetabular impingement syndrome and labral injuries: grading the evidence on diagnosis and non-operative treatment—a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF). British Journal of Sports Medicine. 2021 Nov 1;55(22):1301-10.
9 Kunze KN, Polce EM, Clapp IM, Alter T, Nho SJ. Association Between Preoperative Patient Factors and Clinically Meaningful Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Machine Learning Analysis. The American journal of sports medicine.:3635465211067546.
10 O’Connor M, Steinl GK, Padaki AS, Duchman KR, Westermann RW, Lynch TS. Outcomes of revision hip arthroscopic surgery: A systematic review and meta-analysis. The American Journal of Sports Medicine. 2020 Apr;48(5):1254-62.
11 Sullivan SW, Aladesuru OM, Ranawat AS, Nwachukwu BU. The use of biologics to improve patient-reported outcomes in hip preservation. Journal of Hip Preservation Surgery. 2021 Jan;8(1):3-13.
12 Morris SC, Haselman WT, Banffy MB. Patient Outcomes Are Not Improved by Platelet-Rich Plasma Injection Onto the Capsule at the Time of Closure During Hip Arthroscopy for Femoroacetabular Impingement Syndrome. Arthroscopy, Sports Medicine, and Rehabilitation. 2023 Dec 1;5(6):100816.
13 George T, Curley AJ, Saeed SK, Kuhns BD, Parsa A, Domb BG. Orthobiologics as an adjunct in treatment of femoroacetabular impingement syndrome: cell-based therapies facilitate improved postoperative outcomes in the setting of acetabular chondral lesions—a systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2023 Oct 31:1-9.
14 Ifabiyi M, Patel M, Cohen D, Simunovic N, Ayeni OR. Return-to-sport rates after hip arthroscopy for femoroacetabular impingement syndrome in flexibility sports athletes: a systematic review. Sports health. 2023 Dec 28:19417381231217503.
15 Andronic O, Claydon‐Mueller LS, Cubberley R, Karczewski D, Lu V, Khanduja V. No evidence exists on outcomes of non‐operative management in patients with femoroacetabular impingement and concomitant Tönnis Grade 2 or more hip osteoarthritis: a scoping review. Knee Surgery, Sports Traumatology, Arthroscopy. 2023 Jun;31(6):2103-22.