Conservative Hip Surgery Case Title: Arthroscopic Excision of Intra-articular Osteoid Osteoma of the Femoral Neck

Demographics

1.  

   Age: 22 Sex: Male BMI: 23.7

2. Relevant Past Medical History

    

   Principal pathologies: Intra-articular osteoid osteoma

   Previous surgical procedures: None

   Medication: None

   Other: No known drug allergies

   History of presenting complaint: Z. F. is an otherwise healthy 22-year-old male who presented with sixteen months of insidious onset left groin pain. He described his pain as sharp and aggravated by weight-bearing activities, and he noted intermittent night pain as well. He was initially diagnosed with and treated for, a stress fracture of the femoral neck. He was given NSAIDs and instructed to be partial weight bearing. Three weeks after his initial presentation to an outside hospital, with a history of eight months of hip pain, a CT scan of the hip was performed. It was on CT that an osteoid osteoma was identified in the inferior femoral neck. At that time, the patient chose nonoperative management and eventually weaned off crutches. However, eight months later (a total of sixteen months after initial onset of hip pain), he continued to have persistent left hip pain and sought a second opinion at our institution for his symptoms.

    

3. Clinical Examination

    

   Symptoms: Left anterior hip and groin pain, worse with activity as well as pain at night

   Range of motion: Hip flexion to 85°; internal rotation at 90 degrees of flexion: −5°; and external rotation at 90 degrees of flexion: 15°

   Specific tests: Positive FADIR (flexion, adduction, and internal rotation) and anterior pain with hip flexion

   Main disability: Unable to perform sporting activities and forced to modify daily activities due to left hip pain

   Scoring if available: Preoperative scores, Hip Outcome Score-Activities of Daily Living (HOS-ADL): 83.82; Modified Harris Hip Score (mHHS): 68.2

   Neurovascular evaluation: Normal neurovascular exam

    

    

    

4. Preoperative Radiological Assessment/Imaging (Figs. 1.21, 1.22, and 1.23)

    

    

    

   Fig. 1.23 Preoperative CT scan of characteristic CT findings of osteoid osteoma, demonstrating a nidus with the surrounding sclerotic bone

    

   Fig. 1.21 Preoperative AP pelvis

    

    

    

    

   Fig. 1.22 Preoperative MRI demonstrating significant edema in the femoral neck surrounding the osteoid osteoma lesion

    

5. Preoperative Planning

    

   Diagnosis: Labral tear with cam impingement, synovitis, osteoid osteoma of the femoral neck, and associated sclerosis (Figs. 1.21, 1.22, and 1.23).

   Possible treatment options: Interventional radiology radiofrequency ablation, hip arthroscopy, or open surgical approach to address CAM impingement with excision of osteoid osteoma lesion.

   Chosen treatment method: Hip arthroscopy with CAM decompression and excision of osteoid osteoma lesion.

   Selection of implants if applicable and rational: Standard instrumentation for hip arthroscopy, including arthroscopic electrocautery/radiofre-quency ablation device and arthroscopic burr.

   Expected difficulties: The patient had symptoms consistent with both femoroacetabular impingement and painful osteoid osteoma. We

    

   chose to address his symptoms by repairing the labrum and decompressing his CAM-type femoroacetabular impingement, in addition to excising the osteoid osteoma lesion. The osteoid osteoma was located at the inferior femoral neck, which can be a difficult area to access via hip arthroscopy.

   Strategies to overcome difficulties: Thorough preoperative discussion with the patient regarding our expected technical difficulties and the plan to first address the femoroacetabular impingement pathoanatomy with the goal to also remove the osteoid osteoma if technically possible with hip arthroscopy.

   Templating: Careful examination of preoperative imaging allowed for optimal preoperative planning.

    

6. Surgical Note

    

   Patient’s position: Supine position on a traction table and approximately ten mm of distraction across the femoroacetabular joint.

   Type of anesthesia: Spinal anesthetic and intravenous sedation.

   Surgical approach: Standard lateral, mid-anterior, and distal anterolateral hip arthroscopy portals were utilized.

   Main steps: Diagnostic hip arthroscopy was performed after traction was applied to the hip. An interportal capsulotomy was created between the mid-anterior and lateral portals to access the joint. A wide synovectomy was used to address synovitis in the joint, and a limited labral debridement was completed with a shaver to remove fibrillations of the labrum. The leg was then taken out of traction, and a T-capsulotomy was created to access the femoral head-neck junction, and a CAM decompression was performed with a shaver and burr. The osteoid osteoma lesion was identified, and an arthroscopic burr was used to shell out the lesion from the surrounding bone. The electrocautery device was used to heat this area and remove any residual soft tissue. At the completion of the case, a

   complete capsular closure was performed (Figs. 1.24 and 1.25).

   Reconstruction techniques: Anatomical closure of T-capsulotomy and interportal capsulotomy with interrupted sutures and closure of arthroscopy portals with 3–0 nylon sutures. We used additional sutures to close the extensile T-capsulotomy created to allow for access to the osteoid osteoma lesion.

    

7. Intraoperative Challenges

    

   Challenges and solutions: The location of the osteoid osteoma can present a challenge to arthroscopic access to the lesion. In this particular case, we created an extensile T-capsulotomy to gain access to the osteoid osteoma at the inferior femoral neck. The flexion angle of the hip, as well as external and internal rotation of the leg, can be adjusted using the leg slide of the traction table to allow for instruments to reach the osteoid osteoma.

   Unanticipated problems and solution: Careful preoperative planning prevented any unanticipated problems.

   Thorough description of decision making, including the reason for the final decision: This patient presented with hip pain symptoms that correlated with CAM-type femoroacetabular impingement but could also be related to a symptomatic osteoid osteoma lesion of his inferior femoral neck. While the location of his osteoid osteoma lesion was such that we might not have been able to reach it via an arthroscopic approach, we chose to first attempt hip arthroscopy, with the primary goal to address the bony morphology of his femoroacetabular impingement and the secondary goal to excise the osteoid osteoma lesion. We counseled the patient preoperatively that if we were not able to access the lesion via the arthroscopic technique and he continued to be symptomatic of his osteoid osteoma, other treatment options for this lesion (interventional radiology guidance radiofrequency ablation or open excision of the lesion) may be warranted.

    

8. Postoperative Radiographs

    

    

    

    

    

   Fig. 1.24 Intraoperative radiographic images demonstrating the contour of the femoral head-neck junction prior to and after CAM decompression and osteoid osteoma excision

    

    

    

    

   Fig. 1.25 Intraoperative arthroscopic images showing the osteoid osteoma prior to and after excision with an arthroscopic burr

    

9. Postoperative Management

    

   Chemoprophylaxis and anticoagulant treatment period: a 4-day course of Indocin 75 mg daily for heterotopic ossification prophylaxis. No separate anticoagulant therapy was instituted per standard protocol.

   Gait/limb loading until full loading: Initial toe-touch weight bearing on the operative leg, progressed to full weight bearing by six weeks postoperatively.

    

10. Follow-Up and Complications

     

    Complication: None.

    Scoring: 6-month Hip Outcome Score-Activities of Daily Living (HOS-ADL): 98.53; Hip Outcome Score-Sports Specific (HOS-SS):96.88; Modified Harris Hip Score (mHHS): 95.7; International Hip Outcome Tool-33 (iHot33):88.52; 1-year HOS-ADL: 100; HOS-SS: 100; mHHS:92.4;

    and iHot33:81.77.

     

11. Discussion

     

    Advantages of the applied method: Hip arthroscopy is associated with less morbidity than a surgical hip dislocation or a mini-anterior open approach, yet it allows us to address any central compartment pathology as well as CAM bony morphology as well as the osteoid osteoma lesion. While there are no comparisons of open excision versus arthroscopic excision of intra-articular hip osteoid osteomas, we know that in the treatment of femoroacetabular impingement, hip arthroscopy and the prior standard treatment of open surgical dislocation have equivalent outcomes at medium-term follow-up based on hip-specific patient-reported outcomes [30, 31]. The advantages of hip arthroscopy include higher general health-related quality of life (HRQoL) score and smaller incisions and associated healing when compared to open procedures [30]. Hip arthroscopy has been described in multiple case reports to excision of osteoid

    osteoma of the intra-articular hip joint from both the acetabulum and the femoral neck [32–34].

    Disadvantages of the method: Given the difficulty of accessing the osteoid osteoma, surgical skill and experience are required to appropriately excise the lesion in addition to addressing both the central and peripheral compartment pathology utilizing the arthroscopic technique.

    Alternative evidence-based techniques for the case: Radiofrequency ablation (RFA) is traditionally the standard treatment of osteoid osteomas throughout the body once conservative management (including nonsteroidal anti-inflammatory medications) has failed. The concern with intra-articular osteoid osteomas is the close proximity of the articular cartilage, and the potential for damage due to the high temperatures associated with RFA, as well as skin and muscle burns and damage to nearby neurovascular structures. RFA of intra-articular hip osteoid osteomas has been reported to have a high clinical and technical success rate [35] and is a viable option for patients with this presentation. However, if the patient has concomitant intra-articular hip pathology, RFA alone will not address the entirety of their symptoms as well as hip arthroscopy.

    Why is the chosen technique better for this

    case? Hip arthroscopy, if successful at addressing both the osteoid osteoma lesion and concomitant femoroacetabular impingement, allowed our patient to return to excellent function with a less invasive procedure, with one single procedure, and in a relatively short period of time.

    Indications and contraindications for your technique: The location of the osteoid osteoma lesion will dictate whether it can be accessed arthroscopically. It can be technically very difficult to access the posterior and very inferior femoral neck with arthroscopic instruments. If the osteoid osteoma lesion is in one of these locations, a surgical hip dislocation may be indicated as a single procedure to address both the osteoid osteoma lesion and the femoroacetabular impingement.

    Learning curve and how to manage complications: The learning curve for hip arthroscopy is

     

    substantial, and with lesions located in difficult-to-access regions of the hip joint, excision of osteoid osteomas can be technically very challenging. If hip arthroscopy is attempted and the surgeon is unable to access the osteoid osteoma with arthroscopic instruments, the patient may have to undergo a second procedure—either RFA or open excision. It is therefore important to counsel the patient on this possibility prior to the arthroscopic surgery.

    Level of evidence concerning the superiority of this method against others: Expert opinion.