Chondroblastoma, first delineated by Jaffe and Lichtenstein in 1942, is a rare benign bone tumor accounting for approximately 1%–2% of all bone neoplasms and 9% of benign bone tumors (1, 2). It typically arises in the epiphyses or apophyses of long bones in adolescents and young adults, with a male predominance (2:1 ratio). The femoral head represents an uncommon yet challenging site due to its intra-articular position and critical vascular anatomy. The Direct Anterior Approach (DAA), refined by pioneers such as Smith-Petersen and Judet, utilizes internervous and intermuscular planes to access the hip joint (3, 4). Its application in hip arthroplasty by Matta further established its utility in preserving periarticular soft tissues and minimizing vascular disruption (5). Concurrently, the Surgical Hip Dislocation (SHD) technique, pioneered by Ganz et al., was developed based on detailed vascular studies to allow 360° visualization of the femoral head while safeguarding its blood supply, traditionally involving a trochanteric osteotomy (6). The pathobiology of chondroblastoma has been increasingly elucidated, with mutations in genes encoding histone H3.3 (H3F3B) being implicated in a majority of cases (7, 8). Clinical presentation often includes insidious hip or groin pain, sometimes exacerbated by activity and poorly responsive to analgesics (9). Although benign, chondroblastomas can exhibit aggressive local behavior, and rare instances of pulmonary metastasis or malignant transformation have been documented (10–13). Current therapeutic paradigms emphasize complete tumor excision to mitigate recurrence. Standard surgical options include: (1) minimally invasive curettage via a femoral neck tunnel (Figure 1A), (2) an anterior approach with a femoral neck cortical window (Figure 1B), and (3) surgical hip dislocation for direct articular access (14–18) (Figure 1C). Each technique carries distinct trade-offs regarding exposure completeness, articular cartilage preservation, and risk to the femoral head vasculature and physis. We summarized case reports on the surgical management of femoral head chondroblastoma published over the past two decades (2005–2025) (Table 1) and present a case series in which four adolescent patients with femoral head chondroblastoma underwent tumor resection and articular reconstruction using the Direct Anterior Approach combined with Surgical Hip Dislocation (DAA-SHD) technique, performed in the supine position without trochanteric osteotomy. Additionally, we summarize the clinical features, diagnosis, and treatment of femoral head chondroblastoma, and discuss our clinical experience with this condition.

The DAA-SHD procedure is performed with the patient supine. An 8–10 cm incision is made from the anterior superior iliac spine towards the anterior aspect of the greater trochanter (Figure 2). The Hueter interval between the tensor fasciae latae and sartorius is developed, with care to protect the lateral femoral cutaneous nerve. The lateral femoral circumflex vessels are identified, ligated, and divided. The interval between the rectus femoris (whose reflected head is detached and tagged for later repair) and gluteus medius is entered, exposing the anterior hip capsule.

A T-shaped capsulotomy is performed, meticulously preserving the retinacular vessels along the femoral neck. Under gentle traction and external rotation, the ligamentum teres is transected, permitting anterior hip dislocation. This maneuver provides circumferential access to the femoral head.

Using preoperative imaging and sometimes a 3D-printed model for guidance, a small cartilage window is created directly over the tumor, avoiding the primary weight-bearing dome. The lesion is meticulously curetted, and the sclerotic rim is burred until viable, bleeding bone is encountered. The cavity is irrigated with sterile water and ethanol for adjuvant effect. The resultant defect is grafted using a combination of autologous iliac cancellous bone, allograft chips, calcium sulfate, and osteoinductive materials. For cartilage defects, a contoured autologous iliac cortical bone graft is used to reconstruct the articular surface, secured with absorbable sutures. Following reduction, the capsule and rectus femoris are repaired anatomically. Postoperative management entails a period of non-weight-bearing to protect the reconstruction.

Management of femoral head chondroblastoma must balance complete tumor eradication against the preservation of hip function and vascular integrity. The following surgical approaches are documented in the literature:

Preoperatively, plain x-rays consistently revealed features of benign epiphyseal cartilaginous tumors, including isolated eccentric osteolytic changes that were adjacent to or had penetrated the physeal plate, thinning of the cortical bone, well-defined margins, which might be accompanied by sclerotic rims, and a small amount of intralesional calcifications (these features are more prominent on CT) (21, 22). These findings differ from the typical “soap bubble-like” changes of juvenile giant cell tumors of bone, which generally lack calcifications (23–25). Differential diagnosis should be made with bone-derived tumors and osteoblastomas (which are commonly located in the spine) (26, 27). Additionally, distinction should be drawn from enchondromas, which are characterized by a typical “ring-and-arc” intralesional calcification pattern and expansile osteolytic lesions (28–30). For cases with atypical x-ray findings, further CT and MRI examinations are recommended. All underwent tumor curettage, bone grafting, and autologous iliac cortical bone-supported articular reconstruction via DAA-SHD.

The mean postoperative follow-up was 64.75 months (range: 9–124 months). The Musculoskeletal Tumor Society (MSTS) scale, a validated tool for evaluating post-treatment limb function in bone tumor patients, includes 6 items: pain, functional activity, emotional acceptance, walking ability, gait, and use of Support devices, with a total score of 30 (excellent: 27–30; good: 24–26; fair: 20–23; poor: <20) (31). In this study, all patients achieved excellent functional outcomes, with MSTS scores ranging from 25 to 29 (mean: 27.75, Table 2). Detailed items of the MSTS scale and interpretation of score grades are presented in Table 3 (see footnote a in Table 3). Follow-up imaging demonstrated satisfactory bone graft incorporation, maintenance of femoral head sphericity, and no evidence of AVN, joint degeneration, leg length discrepancy, or tumor recurrence. All patients resumed normal activities without pain or gait abnormality. We presented the follow-up data of one of the patients (Figure 7).

As early as 1972, David C. Dahlin, John C. Ivins based on their pathological studies of 125 case ts, Andrew G. Huvos published pathological findings of 25 chondroblastoma cases in Cancer, proposedhat chondroblastoma is pathologically characterized by the presence of osteoclast-like multinucleated giant cells, cobblestone-like mononuclear oval chondroblasts, eosinophilic chondroid matrix, partial visible calcified tissue, and lattice-like or Pericellular chicken wire-type calcification (32, 33). Later, studies by G. Edel (53 cases), Chandu de Silva (42 cases) and other researchers confirmed these pathological changes, and also verified that the positive expression of S-100 protein in immunohistochemistry can specifically assist in the diagnosis of chondroblastoma (34, 35). We observed these pathological changes in the postoperative pathological tissue sections. Among the immunohistochemical results of the four patients, although the S-100 protein expression was negative in Case 3, its pathological changes were consistent with the diagnosis of chondroblastoma (Figure 8).

The management of femoral head chondroblastoma in children is fraught with the dual challenges of ensuring oncological control and preserving hip development and function. The DAA-SHD approach addresses several limitations of conventional techniques. Oncological Adequacy: Direct visualization ensures complete tumor removal, theoretically reducing recurrence risk compared to blind or fluoroscopically-assisted curettage. Vascular Safety: The DAA respects the posterior vascular structures, primarily the medial femoral circumflex artery, which is the dominant blood supply to the femoral head (36, 37). The avoidance of trochanteric osteotomy further minimizes vascular insult. Articular Surface Restoration: A unique advantage of this approach is the ability to directly address articular cartilage damage. The use of a supportive iliac cortical bone graft to reconstruct the subchondral bone and cover cartilage defects is a key technical nuance that may help prevent joint collapse and post-traumatic arthritis (38). Physeal Preservation: By accessing the tumor directly through the articular surface, the DAA-SHD approach avoids creating a path through the femoral neck, thereby minimizing iatrogenic injury to the physis and reducing the risk of growth disturbance. While the Ganz SHD is a proven technique, the DAA-SHD variant offers a logical alternative, particularly for anteriorly located femoral head pathologies. The supine position aids in orientation and allows for concurrent bilateral hip imaging. The learning curve for this procedure is notable, requiring expertise in hip preservation surgery (39, 40). Comparisons with recently described “trapdoor” techniques without dislocation highlight a strategic difference (41). The DAA-SHD approach intentionally dislocates the hip to gain unrestricted access, which is crucial when the tumor has eroded or breached the cartilage, necessitating direct repair. This controlled dislocation is performed with meticulous attention to vascular preservation, making it a safe maneuver in experienced hands.

The conclusions drawn are constrained by the inherent limitations of a small, single-center case series. The favorable outcomes require validation through larger, prospective studies with long-term follow-up to definitively establish the procedure's efficacy in preventing AVN and osteoarthritis. The technical demands and associated learning curve may limit its widespread adoption.

The supine DAA-SHD approach without trochanteric osteotomy represents a sophisticated and effective surgical strategy for managing chondroblastoma of the femoral head in adolescents. By combining the principles of the DAA and SHD, it facilitates complete tumor excision under direct vision, enables anatomical reconstruction of the articular surface, and minimizes the risk of vascular compromise. This review and case series contribute to the growing body of evidence supporting this technique as a valuable option in the armamentarium for treating complex pediatric hip tumors, warranting further comparative investigation. It is also expected to provide new insights into the surgical treatment of other types of femoral head tumors.