Investigation and macroscopic anatomical study of referred pain in patients with hip disease

Beyond the patella: Treatment of cam femoroacetabular impingement syndrome improves anterior knee pain

OBJECTIVES

This study aimed to investigate if there is a relationship between cam femoroacetabular impingement syndrome (cam-FAIS) and chronic anterior knee pain (AKP).

METHODS

This is a pilot retrospective review of 12 AKP patients with no structural anomalies in the patellofemoral joint and no skeletal malalignment in the lower limbs. All the patients were resistant to proper conservative treatment for AKP (AKP-R). Subsequently, these patients developed pain in the ipsilateral hip several months later, and upon evaluation, were diagnosed with cam-FAIS. Arthroscopic femoral osteoplasty and labral repair were performed and clinical follow-up of hip and knee pain and function (Kujala Score and Non-arthritic Hip Score -NAHS-) was carried out.

RESULTS

All the patients showed improvement in the knee and hip pain scores with a statistically significant clinical difference in all of them at 69 months follow up (range: 18 to 115) except one patient without improvement in the groin VAS score post-operatively. Visual analogical scale (VAS) of knee pain improved from 6.3 (range: 5 to 8) to a postoperative 0.5 (range: 0 to 3.5), (p ​< ​0.001). The VAS of groin pain improved from 4.4 (range: 2 to 8) to a postoperative 0.9 (range: 0 to 3), (p ​< ​0.001). NAHS improved from a preoperative 67.9 (range: 28.7 to 100) to a postoperative 88 (range: 70 to 100), (p ​< ​0.015) and knee Kujala's score improved from a preoperative 48.7 (range: 22 to 71) to a postoperative 96 (range: 91 to 100), (p ​< ​0.001).

CONCLUSION

This study's principal finding suggests an association between cam-FAIS and AKP-R in young patients who exhibit normal knee imaging and lower limbs skeletal alignment. Addressing cam-FAIS in these cases leads to resolution of both groin and knee pain, resulting in improved functional outcomes for both joints.

STUDY DESIGN

Retrospective cohort series with a single contemporaneous long-term follow-up.

LEVEL OF EVIDENCE

IV.

Deep Gluteal Pain Syndrome: Endoscopic Technique and Medium-Term Functional Outcomes

BACKGROUND

Sciatic nerve entrapment is an entity that generates disabling pain, mainly when the patient is sitting on the involved side. According to some studies, the presence of fibrovascular bands has been described as the main cause of this pathology, and the sciatic nerve's decompression by endoscopic release has been described as an effective treatment generally associated with a piriformis tenotomy. The aim of this study was to present the medium-term functional results of endoscopic release of the sciatic nerve without resection of the piriformis tendon.

METHODS

This prospective, observational study included 57 patients who underwent an endoscopic operation for sciatic nerve entrapment between January 2014 and January 2019. In all cases, a detailed medical history was obtained and a physical examination and a functional evaluation were performed using the modified Harris hip score (mHHS), the 12-item International Hip Outcome Tool (iHOT-12), and the visual analog scale (VAS) for pain. All patients had pelvic radiographs and magnetic resonance imaging (MRI) scans of the hip on the involved side and underwent a prior evaluation by a spine surgeon.

RESULTS

This study included 20 male and 37 female patients with a mean age of 43.6 years (range, 24 to 88 years) and a mean follow-up of 22.7 months. The median mHHS improved from 59 to 85 points. The median iHOT-12 improved from 60 to 85 points. The median VAS decreased from 7 to 2. Postoperative complications occurred in 12% of patients: 1 patient with extensive symptomatic hematoma, 3 patients with hypoesthesia, and 3 patients with dysesthesia.

CONCLUSIONS

Endoscopic release of the sciatic nerve by resection of fibrovascular bands without piriformis tenotomy is a technique with good to excellent functional results comparable with those of techniques in the literature incorporating piriformis tenotomy.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Secondary osteonecrosis of the knee as a part of long COVID-19 syndrome: a case series

COVID-19 infection affects different organ systems with long-term sequelae, which has been termed as long COVID-19 syndrome. To the best of our knowledge, osteonecrosis of the knee as a part of long COVID-19 syndrome has not been documented. Corticosteroids are being used extensively in moderate and severe cases of COVID-19. We report two cases who developed osteonecrosis of the knee after being treated for COVID-19 infection. In our case series, the mean cumulative dose of prednisolone was 1156.5 mg (900-1413 mg), which is less than the cumulative dose reported in literature for osteonecrosis of the knee. In our case series, the patients developed symptomatic osteonecrosis at a mean interval of 73 days after initiation of steroid therapy, with the earliest presenting at 25 days. Early diagnosis of osteonecrosis of the knee on high clinical suspicion by MRI would help in early intervention with bisphosphonate therapy.

Sensory Innervation of the Hip Joint and Referred Pain: A Systematic Review of the Literature

OBJECTIVES

The aim of this literature review was to establish consensus with respect to the anatomic features of the articular branches innervating the hip joint and the distribution of sensory receptors within its capsule.

METHODS

Five electronic databases were queried, with the search encompassing articles published between January 1945 and June 2019. Twenty-one original articles providing a detailed description of sensory receptors around the hip joint capsule (n=13) and its articular branches (n=8) were reviewed.

RESULTS

The superior portions of the anterior capsule and the labrum were found to be the area of densest nociceptive innervation. Similar to the distribution of nociceptors, mechanoreceptor density was found to be higher anteriorly than posteriorly. Hip joint capsular innervation was found to consistently involve the femoral and obturator nerves, which supply the anterior capsule, and the nerve to the quadratus femoris, which supplies the posterior capsule. The femoral, obturator, and superior gluteal nerves supply articular branches to the most nociceptor-rich region of the hip capsule.

CONCLUSIONS

The femoral and obturator nerves and the nerve to the quadratus femoris were found to consistently supply articular branches to both the anterior and posterior capsule of the hip joint. The anterior capsule, primarily supplied by the femoral and obturator nerves, and the superior labrum appear to be the primary pain generators of the hip joint, given their higher density of nociceptors and mechanoreceptors.

LEVEL OF EVIDENCE

Anatomy study, literature review.

A systematic review and meta-analysis of the hip capsule innervation and its clinical implications

Detailed understanding of the innervation of the hip capsule (HC) helps inform surgeons’ and anaesthetists’ clinical practice. Post-interventional pain following radiofrequency nerve ablation (RFA) and dislocation following total hip arthroplasty (THA) remain poorly understood, highlighting the need for more knowledge on the topic. This systematic review and meta-analysis focuses on gross anatomical studies investigating HC innervation. The main outcomes were defined as the prevalence, course, density and distribution of the nerves innervating the HC and changes according to demographic variables. HC innervation is highly variable; its primary nerve supply seems to be from the nerve to quadratus femoris and obturator nerve. Many articular branches originated from muscular branches of the lumbosacral plexus. It remains unclear whether demographic or anthropometric variables may help predict potential differences in HC innervation. Consequently, primary targets for RFA should be the anterior inferomedial aspect of the HC. For THA performed on non-risk patients, the posterior approach with capsular repair appears to be most appropriate with the lowest risk of articular nerve damage. Care should also be taken to avoid damaging vessels and muscles of the hip joint. Further investigation is required to form a coherent map of HC innervation, utilizing combined gross and histological investigation.

The Extent of Pain Is Associated With Signs of Central Sensitization in Patients With Hip Osteoarthritis

BACKGROUND

Central sensitization may be present in some patients with hip osteoarthritis (OA), often reflected as widespread pain. We examine the association between pain extent with signs of central sensitization and other clinical and psychological features in patients with hip OA.

METHODS

Thirty patients with hip OA were recruited for this cross-sectional observational study. Participants completed pain drawings on a digital tablet, which displayed frontal and dorsal views of the body. The pain extent (%) for each participant was determined by combining the frontal and dorsal pixels shaded and dividing by the total pixels of the body chart area. Participants completed patient-reported outcome measures to assess for signs and symptoms of central sensitization and psychosocial factors. Quantitative sensory testing including pain pressure thresholds (PPTs) and thermal pressure thresholds was performed at points anatomically local and distant from the hip.

RESULTS

Women had significantly greater pain extent (6.71%) than men (2.65%) (z = -2.76, P < 0.01). Across all participants, increased pain extent was significantly associated with higher scores on the Widespread Pain Index (r₂  = 0.426, P < 0.05), painDETECT questionnaire (r₂  = 0.394, P < 0.05), and Pain Catastrophizing Scale (r₂  = 0.413, P < 0.05), and with lower PPTs at the thenar eminence (r₂  = -0.410, P < 0.05), vastus lateralis (r₂  = -0.530, P < 0.01), vastus medialis (r₂  = 0.363, P < 0.05), and greater trochanter (r₂  = -0.373, P < 0.05).

CONCLUSIONS

Greater pain extent was associated with several measures of signs and symptoms of central sensitization in patients with hip OA. These results support the utility of the pain drawing for identifying signs of central sensitization in patients with hip OA.

Hip-related groin pain, patient characteristics and patient-reported outcomes in patients referred to tertiary care due to longstanding hip and groin pain: a cross-sectional study

BACKGROUND

Due to advances in hip arthroscopy, the number of surgical procedures has increased dramatically. The diagnostic challenge in patients with longstanding hip and groin pain, as well as the increasing number of hip arthroscopies, may lead to a higher number of patients referred to tertiary care for consideration for surgery. Therefore, the aims were: 1) to describe the prevalence of hip-related groin pain in patients referred to tertiary care due to longstanding hip and groin pain; and 2) to compare patient characteristics and patient-reported outcomes for patients categorized as having hip-related groin pain and those with non-hip-related groin pain.

METHODS

Eighty-one patients referred to the Department of Orthopedics at Skåne University Hospital for longstanding hip and groin pain were consecutively included and categorized into hip-related groin pain or non-hip-related groin pain using diagnostic criteria based on current best evidence (clinical examination, radiological examination and intra-articular block injection). Patient characteristics (gender (%), age (years), BMI (kg/m²)), results from the Hip Sports Activity Scale (HSAS), the SF-36, the Copenhagen Hip and Groin Outcome Score (HAGOS), and pain distribution (pain manikin) were collected. Parametric and non-parametric statistics were used as appropriate for between-group analysis.

RESULTS

Thirty-three (47%) patients, (30% women, 70% men, p < 0.01), were categorized as having hip-related groin pain. The hip-related groin pain group had a higher activity level during adolescence (p = 0.013), and a higher pre-injury activity level (p = 0.034), compared to the non-hip-related groin pain group. No differences (mean difference (95% CI)) between hip-related groin pain and non-hip-related groin pain were observed for age (0 (- 4; 4)), BMI (- 1.75 (- 3.61; 0.12)), any HAGOS subscales (p ≥ 0.318), any SF-36 subscales (p ≥ 0.142) or pain distribution (p ≥ 0.201).

CONCLUSIONS

Only half of the patients referred to tertiary care for long-standing hip and groin pain, who were predominantly men with a high activity level, had hip-related groin pain. Self-reported pain localization and distribution did not differ between patients with hip-related groin pain and those with non-hip-related groin pain, and both patient groups had poor perceived general health, and hip-related symptoms and function.

Don't forget the hip! Hip arthritis masquerading as knee pain

Background

Hip osteoarthritis typically manifests with groin or thigh pain. Other atypical pain patterns, including knee pain, have been described. Except for 2 case reports, there is no literature on this subject.

Methods

From our institutional database, between 2011 and 2016, we identified 21 patients who were referred for treatment of knee pain but ultimately diagnosed with hip pathology as the cause of their pain. This group was evaluated for duration of symptoms prior to diagnosis, previous interventions, presence of walking aids, and symptom resolution after treatment of the hip pathology.

Results

Fifteen of the 21 patients were referred from musculoskeletal providers (12 from orthopaedic surgeons). Prior to diagnosis of the hip etiology, 16 patients were reduced to major assistive devices including wheelchairs. Twelve of 21 patients had undergone surgical knee interventions, including total knee arthroplasty, with minimal to no relief of their pain. Seventeen of 21 referred patients underwent total hip arthroplasty at our institution. Fourteen patients had complete resolution of knee pain after total hip arthroplasty.

Conclusions

Although knee pain referred from hip disease may be considered a basic and common knowledge, it continues to be an overlooked phenomenon. Most of the cases were misdiagnosed by musculoskeletal providers including orthopaedic surgeons and this highlights the need for continued education and awareness of this clinical scenario.

Posterior, Lateral, and Anterior Hip Pain Due to Musculoskeletal Origin: A Narrative Literature Review of History, Physical Examination, and Diagnostic Imaging

OBJECTIVE

The purpose of this study was to present a narrative review of the literature of musculoskeletal causes of adult hip pain, with special attention to history, physical examination, and diagnostic imaging.

METHODS

A narrative review of the English medical literature was performed by using the search terms "hip pain" AND "anterior," "lateral," and "posterior." Additionally, specific entities of hip pain or pain referral sources to the hip were searched for. We used the PubMed search engine through January 15, 2016.

RESULTS

Musculoskeletal sources of adult hip pain can be divided into posterior, lateral, and anterior categories. For posterior hip pain, select considerations include lumbar spine and femoroacetabular joint referral, sacroiliac joint pathology, piriformis syndrome, and proximal hamstring tendinopathy. Gluteal tendinopathy and iliotibial band thickening are the most common causes of lateral hip pain. Anterior hip pain is further divided into causes that are intra-articular (ie, labral tear, osteoarthritis, osteonecrosis) and extra-articular (ie, snapping hip and inguinal disruption [athletic pubalgia]). Entrapment neuropathies and myofascial pain should also be considered in each compartment. A limited number of historical features and physical examination tests for evaluation of adult hip pain are supported by the literature and are discussed in this article. Depending on the clinical differential, the gamut of diagnostic imaging modalities recommended for accurate diagnosis include plain film radiography, computed tomography, magnetic resonance imaging, skeletal scintigraphy, and ultrasonography.

CONCLUSIONS

The evaluation of adult hip pain is challenging. Clinicians should consider posterior, lateral, and anterior sources of pain while keeping in mind that these may overlap.

Pain distribution in primary care patients with hip osteoarthritis

BACKGROUND

Hip osteoarthritis (OA) is the most common diagnosis in primary care adult patients presenting with hip pain but pain location and pain distribution in primary care patients with hip OA have been reported inadequately.

OBJECTIVE

To describe pain location and pain distribution in primary care patients with clinical and radiographic confirmed hip OA.

METHODS

Primary care patients with unilateral clinical and radiographic hip OA living on the island of Funen, Denmark were recruited from primary care to participate in a randomized clinical trial. At baseline, patients recorded pain intensity using an 11-box numeric rating scale and the distribution of hip pain using a manikin displaying three separate views: front, back and lateral. Pain drawings were analysed using a template to determine the most frequent pain locations and distribution of pain.

RESULTS

Pain drawings were completed by 109 patients of which 108 (99%) were valid. The mean age of patients was 65 (SD 9) years and 44% were females. The mean pain intensity was 5.4 (SD 2.0). A total of 77% had marked the greater trochanter area, 53% the groin area, 42% the anterior/lateral thigh area, 38% the buttock area, 17% the knee and 15% the lower leg area. No patients marked pain exclusively in the areas of the knee, posterior thigh or lower leg.

CONCLUSION

The most common pain locations of patients with hip OA presenting to primary care are the greater trochanter, groin, thigh and buttock areas. No patients recorded pain exclusively in the knee or lower leg.

Treatment of trochanteric bursitis: our experience

[Purpose] Trochanteric bursitis is a disease for which there are no effective standardized therapy protocols. Very often pain persists in spite of applying all therapeutic treatments. The purpose of this study was to determine whether treatment of trochanteric bursitis with a local injection of bicomponent corticosteroid and 2% lidocaine would improve patients’ conditions and relieve pain symptoms in the trochanteric area. [Subjects and Methods] A retrospective observational study was conducted of 2,217 patients in a 6 year follow-up period at the Special Hospital “Agens”, Mataruska Banja, Serbia. [Results] Of 2,217 examined patients, 58 (2.6%) patients were found to suffer from trochanteritis associated with low back pain, and 157 (7%) were found to suffer from trochanteric pains without low back pains. Local corticosteroid therapy followed by physical therapy was effective in 77 (49%) of these patients, and only corticosteroid injection in 61 (39%) patients. A single injection was given to 47 (29.9%) of the patients. Two injections were given to 9 (5.7%) patients, and from 3 to 5 injections were given repeatedly every 4–6 weeks to 7 (4.5%) patients. [Conclusion] For most patients, local injections of corticosteroids with lidocaine alone or followed by physical therapy gave satisfactory results.

A clinical comparative study of anatomic parameters before and after total hip replacement on congenital dysplasia

[Purpose] To study preoperative and postoperative hip circumference data of various types of congenital dysplasia of the hip treated with total hip replacement, including the femoral offset, femoral neck length, height, and hip abductor arm parameters. [Subjects and Methods] This study included seventy-eight cases of congenital dysplasia of the hip (I–III type). Furthermore, four parameters were measured, including the preoperative and postoperative femoral offset. Statistical data analysis was performed using the SPSS 13.0 software. [Results] The femoral offset was 33.3 ± 8.4 mm (preoperative) and 39.1 ± 7.1 mm (postoperative). The femoral head height was 59.5 ± 8.7 mm (preoperative) and 68.8 ± 11.0 mm (postoperative). The femoral neck length was 50.8 ± 10.8 mm (preoperative) and 61.5 ± 10.4 mm (postoperative). The hip abductor arm was 54.3 ± 9.6 mm (preoperative) 64.7 ± 10.1 mm (postoperative). The preoperative and postoperative parameters showed statistical differences. Furthermore, no significant differences were evidenced when comparing the postoperative hip parameters with the normal data parameters. [Conclusion] Total hip replacement on congenital dysplasia of the hip could lead to the rebuilt of an almost normal physiological anatomy for each hip case (type I–III).

Legg-Calvé-Perthes Disease

Legg-Calve-Perthes disease (LCPD) is the insidious onset of idiopathic avascular necrosis of the hip in the pediatric population. The disease encompasses a wide spectrum of pathology, from mild with no long-term sequelae to severe with permanent degenerative change of the hip joint. A pediatric patient with hip pathology may initially only present with knee or thigh pain, thus obligating the clinician to maintain awareness about the hip during examination. Common physical examination findings include deficits in hip abduction and internal rotation, along with Trendelenburg gait in late stages. Plain radiographs demonstrate changes in the anterolateral aspect of the femoral head, sometimes only seen on the frog lateral X-ray in early stages. Treatment options aim to restore range of motion and maintain adequate coverage of the femoral head. When appropriate, surgery is used to reorient the femoral head or pelvis to maintain coverage.

Do persons with asymmetric hip pain or radiographic hip OA have worse pain and structure outcomes in the knee opposite the more affected hip? Data from the Osteoarthritis Initiative

PURPOSE

To determine if asymmetry between hips in pain or radiographic osteoarthritis (RHOA) is associated with worse pain and joint space narrowing (JSN) at baseline and longitudinally in knees contralateral to more affected hips.

METHODS

We studied 279 participants in the Osteoarthritis Initiative with baseline asymmetry between hips in pain and 483 with asymmetry in RHOA none of whom had a hip replacement for ≥4 years after baseline. RHOA assessed from pelvis radiographs was categorized as none, possible or definite and hip pain on most days of a month in the past year as present/absent. Knee pain (WOMAC scale) and JSN (fixed flexion radiographs) were categorized as none, mild and moderate-severe. We compared knees contralateral and ipsilateral to more affected hips on baseline knee pain and JSN using clustered multinomial regression and on change in knee pain and JSN over 4-5 years using generalized linear and logistic estimating equations.

RESULTS

Knees contralateral to painful hips had less baseline pain ("moderate-severe" vs "none", relative risk ratio [RRR]: 0.39, 95% CI = 0.27-0.57), but greater baseline JSN ("moderate-severe" vs "none", RRR: 1.62, 95% CI = 1.09-2.38) and greater worsening of pain during follow-up (P = 0.001). Knees contralateral to hips with worse RHOA had nonsignificant trends for greater baseline JSN (P = 0.10) and JSN progression (P = 0.17).

CONCLUSION

These findings provide limited support for the hypothesis that early asymmetry in hip pain and RHOA is associated with worse pain and structural outcomes in knees contralateral to the more affected hip.

A clinical study of the rotational alignment of the femoral component in total knee arthroplasty

[Purpose] The reasons for femorotibial rotational malalignment after total knee arthroplasty (TKA) were analyzed to provide evidence for clinical knee joint surgery and to reduce complications. [Subjects and Methods] Ninety knees of 60 patients were selected and randomly divided into two groups (n=30). For one group, rotational alignment of the femoral component was determined by the transepicondylar axis and TKA was performed. For the other group, rotational alignment of the femoral component was conducted through 3° external rotation of the posterior femoral condyles. Knee joint specimens were operated with TKA and various biomechanical indices were measured. [Results] The femoral epicondylar axis was a constant, reliable reference for femoral component rotational alignment. When the femoral component was rotated by 0° versus the epicondylar axis, the peak contact pressure on the patellofemoral joint was optimal. When the femoral component was arranged in parallel with Whiteside's line, the peak contact pressure on the patellofemoral joint varied largely. The patellofemoral contact areas of the two groups were similar. [Conclusion] Axial rotational alignment of the femoral component influenced the contact pressure of patellofemoral joints in TKA more significantly than external rotation of the femoral condyles. It is more reliable to use the femoral epicondylar axis as the reference for the rotational alignment of the femoral component.