Orthopedics

Case Reports 

Treatment of Focal Osteochondral Defects of the Acetabulum With Osteochondral Allograft Transplantation

Aaron J. Krych, MD; Dean G. Lorich, MD; Bryan T. Kelly, MD

Abstract

To our knowledge, treatment of focal osteochondral defects of the acetabulum with osteochondral allograft transplantation has not been described. As with osteochondral lesions of other weight-bearing surfaces, these defects may lead to disabling pain and early degenerative changes. In older patients who fail nonoperative treatment, hip arthroplasty is a reliable option to obtain pain relief and restore function. However, in young and active patients, it may be advantageous to restore joint congruity biologically. The clinical success of osteochondral allograft transplantation in the femoral condyles has been well-documented, with over 25 years of experience. We propose similar treatment principles in the hip joint.

This article presents the cases of a 24-year-old woman (patient 1) and a 32-year-old man (patient 2) with hip pain and dysfunction secondary to a focal osteochondral defect of the acetabulum. Both were treated with osteochondral allograft transplantation to the defect using a dowel technique. A magnetic resonance image at 18 months in both cases demonstrated incorporation of the allograft bone into the host acetabulum. At 24 months in patient 1 and 42 months in patient 2, radiographs showed no progressive osteoarthritis. Both patients’ Hip Outcome Scores were 100 points each.

Osteochondral allografts allow large areas to be resurfaced without donor site morbidity, and these grafts provide an immediate functional joint surface. Although it has not been proven in terms of long-term follow-up, we believe that osteochondral allograft transplantation for focal osteochondral defects of the acetabulum in young, active patients is a feasible option to restore joint congruity.

Drs Krych, Lorich, and Kelly are from the Hospital for Special Surgery, Weill Medical College of Cornell University, New York, New York.

Drs Krych, Lorich, and Kelly have no relevant financial relationships to disclose.

Chondral lesions of the hip are gaining in recognition as a source of pain and dysfunction in the hip joint due to increased detection by hip arthroscopy, and improved imaging techniques with magnetic resonance imaging (MRI) over the past decade. Treatment options, including arthroscopic chondroplasty and microfracture, are evolving due to advances in surgical techniques. 1 However, focal osteochondral defects in the acetabulum are uncommon, with limited treatment options available to the surgeon. A variety of procedures and treatments have been proposed to lessen symptoms and restore osteochondral integrity in the knee joint, although little information exists regarding treatment of the hip, and management remains poorly defined. As with osteochondral defects of other weight-bearing surfaces, these defects may lead to intractable pain and early degenerative changes. 2 Potential treatment options for a focal osteochondral defect of the acetabulum include autologous osteochondral tissue transfer or allograft tissue transplantation. The goal of these biologic reconstructive techniques is pain-free range of motion (ROM) by restoring the congruity of the articular surface and preserving normal joint kinematics. Osteochondral allograft transplantation for localized defects in the knee has a 75% to 85% rate of subjective improvement in patients at 3- to 10-year follow-up. 3–9 We hypothesize that using similar methods to reconstruct symptomatic osteochondral defects of the acetabulum may preserve the hip joint and provide a useful way to treat patients with substantial pain and associated disability.

This article presents 2 cases of patients with focal osteochondral defects of the acetabulum treated with osteochondral allograft transplantation.

A 24-year-old active female college student presented with progression of groin pain, exacerbated by weight-bearing activities after failing arthroscopic femoral neck osteoplasty performed elsewhere. On examination, she had limited motion with flexion to 100°, internal rotation to 10°, and positive anterior impingement signs (pain reproduced with flexion, adduction, and internal rotation of the hip). Presenting radiographic studies demonstrated a 1- to 2-cm osteochondral defect over…

Abstract

To our knowledge, treatment of focal osteochondral defects of the acetabulum with osteochondral allograft transplantation has not been described. As with osteochondral lesions of other weight-bearing surfaces, these defects may lead to disabling pain and early degenerative changes. In older patients who fail nonoperative treatment, hip arthroplasty is a reliable option to obtain pain relief and restore function. However, in young and active patients, it may be advantageous to restore joint congruity biologically. The clinical success of osteochondral allograft transplantation in the femoral condyles has been well-documented, with over 25 years of experience. We propose similar treatment principles in the hip joint.

This article presents the cases of a 24-year-old woman (patient 1) and a 32-year-old man (patient 2) with hip pain and dysfunction secondary to a focal osteochondral defect of the acetabulum. Both were treated with osteochondral allograft transplantation to the defect using a dowel technique. A magnetic resonance image at 18 months in both cases demonstrated incorporation of the allograft bone into the host acetabulum. At 24 months in patient 1 and 42 months in patient 2, radiographs showed no progressive osteoarthritis. Both patients’ Hip Outcome Scores were 100 points each.

Osteochondral allografts allow large areas to be resurfaced without donor site morbidity, and these grafts provide an immediate functional joint surface. Although it has not been proven in terms of long-term follow-up, we believe that osteochondral allograft transplantation for focal osteochondral defects of the acetabulum in young, active patients is a feasible option to restore joint congruity.

Drs Krych, Lorich, and Kelly are from the Hospital for Special Surgery, Weill Medical College of Cornell University, New York, New York.

Drs Krych, Lorich, and Kelly have no relevant financial relationships to disclose.

Correspondence should be addressed to: Aaron J. Krych, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (krych.aaron@mayo.edu).
Posted Online: July 07, 2011

Chondral lesions of the hip are gaining in recognition as a source of pain and dysfunction in the hip joint due to increased detection by hip arthroscopy, and improved imaging techniques with magnetic resonance imaging (MRI) over the past decade. Treatment options, including arthroscopic chondroplasty and microfracture, are evolving due to advances in surgical techniques. 1 However, focal osteochondral defects in the acetabulum are uncommon, with limited treatment options available to the surgeon. A variety of procedures and treatments have been proposed to lessen symptoms and restore osteochondral integrity in the knee joint, although little information exists regarding treatment of the hip, and management remains poorly defined. As with osteochondral defects of other weight-bearing surfaces, these defects may lead to intractable pain and early degenerative changes. 2 Potential treatment options for a focal osteochondral defect of the acetabulum include autologous osteochondral tissue transfer or allograft tissue transplantation. The goal of these biologic reconstructive techniques is pain-free range of motion (ROM) by restoring the congruity of the articular surface and preserving normal joint kinematics. Osteochondral allograft transplantation for localized defects in the knee has a 75% to 85% rate of subjective improvement in patients at 3- to 10-year follow-up. 3–9 We hypothesize that using similar methods to reconstruct symptomatic osteochondral defects of the acetabulum may preserve the hip joint and provide a useful way to treat patients with substantial pain and associated disability.

This article presents 2 cases of patients with focal osteochondral defects of the acetabulum treated with osteochondral allograft transplantation.

Case Reports

Patient 1

A 24-year-old active female college student presented with progression of groin pain, exacerbated by weight-bearing activities after failing arthroscopic femoral neck osteoplasty performed elsewhere. On examination, she had limited motion with flexion to 100°, internal rotation to 10°, and positive anterior impingement signs (pain reproduced with flexion, adduction, and internal rotation of the hip). Presenting radiographic studies demonstrated a 1- to 2-cm osteochondral defect over the weight-bearing dome consistent in appearance with a periacetabular cyst, and evidence of an incomplete femoral neck osteoplasty (Figure ).

Preoperative coronal (A) and sagittal (B) CT scans demonstrating the 15-mm osteochondral defect of the superior dome of the acetabulum. Axial CT scan demonstrating incomplete femoral neck osteoplasty (arrows) (C).

Figure 1:. Preoperative coronal (A) and sagittal (B) CT scans demonstrating the 15-mm osteochondral defect of the superior dome of the acetabulum. Axial CT scan demonstrating incomplete femoral neck osteoplasty (arrows) (C).

Patient 2

A 32-year-old man presented with 2 previous open hip operations for fibrous dysplasia. The first operation, performed 5 years prior to presentation, included open curettage and grafting of a biopsy-proven fibrous dysplasia lesion of the supra-acetabular region. The patient had progression of the lesion and continued pain, and therefore underwent a subsequent revision open curettage and placement of bone cement within the defect 2 years prior to presentation.

Following the second open procedure, he had initial pain relief. However, 1 year later, the patient presented with progressive groin pain and dysfunction in the hip that had not responded to nonoperative treatment. Physical examination demonstrated an antalgic gait, ROM with flexion to 110°, internal rotation to 10°, and external rotation to 40°, and pain with flexion, internal rotation, and adduction of the hip. Radiographs were consistent with cement protruding into the hip joint (Figure ). Therefore, the cement was removed through an open approach. Biopsy at that time revealed no active fibrous dysplasia lesion. However, he continued to have pain, especially with any weight-bearing activity. Having failed nonoperative management, we proceeded with operative treatment.

Preoperative axial (A) and sagittal (B) CT scans demonstrating bone cement at the articular surface of the acetabulum.

Figure 2:. Preoperative axial (A) and sagittal (B) CT scans demonstrating bone cement at the articular surface of the acetabulum.

For both patients, the surgical approach included a standard trochanteric osteotomy followed by surgical hip dislocation performed in the lateral decubitus position. Patient 1 had an 18×18-mm isolated defect of the superior acetabular dome (Figure ), without damage of surrounding articular surfaces of the acetabulum or femoral head. Patient 2 had a 12-mm diameter×10-mm deep osteochondral defect in the weight-bearing dome of the superior acetabulum. In both patients, the Arthrex Mega-OATS osteochondral allograft system (Arthrex, Inc, Naples, Florida) was used to create an osteochondral dowel allograft the same size as the defect.

Intraoperative photographs demonstrating an 18-mm osteochondral defect covered with fibrous tissue outlined in blue marker in the weight-bearing dome of the acetabulum (A); a guide pin placed perpendicular to the osteochondral defect and the recipient site prepared with reamers (B); acetabular donor allograft with guide pin in the same anatomic location as the recipient site in the patient (C); the depth of the free osteochondral allograft fashioned precisely to correspond to the depth reamed in the donor site (D); and press-fit placement of the donor allograft into the recipient osteochondral defect in the acetabulum (E).

Figure 3:. Intraoperative photographs demonstrating an 18-mm osteochondral defect covered with fibrous tissue outlined in blue marker in the weight-bearing dome of the acetabulum (A); a guide pin placed perpendicular to the osteochondral defect and the recipient site prepared with reamers (B); acetabular donor allograft with guide pin in the same anatomic location as the recipient site in the patient (C); the depth of the free osteochondral allograft fashioned precisely to correspond to the depth reamed in the donor site (D); and press-fit placement of the donor allograft into the recipient osteochondral defect in the acetabulum (E).

The recipient site preparation included using a reamer over a guide-pin perpendicular to the articular surface (Figure ). In patient 1, the donor graft consisted of an allograft acetabulum (Figure ); in patient 2, a medial tibial plateau donor graft was chosen in the area of maximum joint concavity to match the geometry of the acetabular defect allograft. Both grafts were fresh-stored, nonirradiated osteochondral allografts obtained from the Musculoskeletal Transplant Foundation (Edison, New Jersey). The allograft dowels were fashioned precisely to correspond to the depth of the osteochondral defect of the acetabulum (Figure ). In both cases, press-fitting the osteochondral graft into place permitted excellent stability, without supplemental fixation (Figure ).

Due to the patients’ concomitant cam lesion, re-establishment of normal femoral head-neck offset required an open femoral neck osteoplasty. Capsule repair included suture anchors placed in the superior acetabulum; the trochanteric osteotomy fixation included 2 bicortical screws. Postoperative management included a combination of 8 weeks of protected weight bearing and 8 to 10 hours of daily use of continuous passive motion. Running and other high impact activities began at 6 months postoperatively.

Both patients’ pain improved significantly postoperatively, as did their walking ability. An MRI performed 12 months postoperatively in patient 1 (Figure ) and 18 months postoperatively in patient 2 demonstrated incorporation of the osteochondral allograft to the host bone with maintenance of joint congruity. At 24 months in patient one and 42 months in patient two, radiographs showed no progressive joint space narrowing compared to preoperative radiographs (Figure ). Patient 1 had improvement in modified Harris Hip Score from 75 preoperatively to 97 at 2-year follow-up. The modified Harris Hip Score improved from 79 preoperatively to 100 at the time of 3-year follow-up in patient 2. Both patients’ Hip Outcome Score subsets for activities of daily living and sports score 10 were 100 points each.

Coronal (A) and sagittal (B) metal-suppression MRIs demonstrating consolidation of the osteochondral allograft (arrows) to the host bone and restoration of joint congruity.

Figure 4:. Coronal (A) and sagittal (B) metal-suppression MRIs demonstrating consolidation of the osteochondral allograft (arrows) to the host bone and restoration of joint congruity.

Standing AP pelvic radiograph of patient 1 at 2-year follow-up demonstrating no progressive joint space narrowing.

Figure 5:. Standing AP pelvic radiograph of patient 1 at 2-year follow-up demonstrating no progressive joint space narrowing.

Discussion

We introduce transplantation of an osteochondral dowel allograft as a new surgical option for reconstruction of a focal osteochondral defect in the acetabulum. Several case reports and small case series report osteochondral allograft of focal osteochondral defects of the femoral head in the setting of: avascular necrosis, 11 osteochondritis dissecans, 12 and fracture-dislocation of the femoral head with post-traumatic defects. 13 Additionally, defects in the pelvis have been reconstructed with a pelvic allograft after resection of malignant bone tumors. 14 However, to our knowledge, no published reports of osteochondral allograft reconstruction in the acetabulum for focal osteochondral defects exist.

Osteochondral allografts allow large areas of resurfacing without the donor site morbidity associated with autologous osteochondral transfer. 15 Additionally, these grafts provide an immediate functional joint surface. The underlying principle of an osteochondral allograft is transplantation of hyaline articular cartilage along with structural bone into the defect. 16 In the knee, osteochondral allograft transplantation is indicated for treatment of larger lesions (>2.5 cm 2) or those with substantial bone loss. 9 In the cases presented, the substantial bone loss precluded the use of other cartilage restoration techniques.

We support that, as in the knee, the osteochondral defect in the acetabulum must be a localized, unipolar lesion. Special considerations for placing an osteochondral dowel graft in the hip include sizing and matching the native articular geometry of the joint. As noted previously, matching of the geometry of the graft and the recipient site facilitates the long-term survival of the graft. 15 In the presented cases, we used both an acetabular and a medial tibial plateau allograft. Comparing the 2 grafts, we felt matching of the recipient site was best achieved using the maximum concavity of a medial tibial plateau allograft. The advantage of using the medial tibial plateau is that the cartilage has a thickness of 2.5+0.6 mm at its maximum concavity, 16 which is thicker than at the apex of an allograft acetabulum, which averages 1.7+0.1 mm, but can vary depending on the geographic region of the acetabulum. 17 A further advantage of using a medial tibial plateau allograft is its relative availability in tissue banks.

Though osteochondral autograft transfer is also an option in focal osteochondral acetabular defects, it is limited to relatively small- or medium-sized defects due to donor-site morbidity. 18,19 Hangody and Fules 18 included 6 femoral head osteochondral autograft transfers in their reported series of 831 patients undergoing mosaicplasty, but there is no subset analysis of the outcome of these patients. Other limitations of osteochondral autograft transfer in this case would be violation of a normal knee joint, as well as difficulty matching the geometry of the plugs to the defect site in the concave acetabulum. A recent case report suggests that an autologous osteochondral plug may be harvested from a relatively nonweight-bearing portion of the femoral head-neck junction, but this is relatively limited in size. 20 Another alternative surgical consideration in these young, high demand patients would be arthroplasty. However, the 2 patients did not desire this option, and we felt preservation of the hip joint was feasible.

The main limitation of this report is that in the 2 patients, there is not only an osteochondral defect, but also cam femoroacetabular impingement. In our experience, the history and physical examination of the hip is the most useful and effective way to diagnose and treat hip disorders. In these 2 patients, both presented with a history suggestive of impingement (sharp anterior pain with deep flexion, internal rotation, or abduction). 21

The physical examination confirmed positive impingement signs with limited flexion and internal rotation, and reproduction of groin pain at 90° of flexion, adduction, and maximal internal rotation. However, both patients also had a dull, aching pain with limited walking on level ground, more suggestive of joint incongruity from an osteochondral lesion. Although osteochondral injuries may be associated with mechanical symptoms, no specific examination maneuver exists to assess for them. It is also conceivable that the impingement worsened the symptoms of the osteochondral lesion, as cam impingement often causes damage of the articular cartilage at the chondrolabral junction. 1 Even if the patients in this study had asymptomatic cam lesions of the femoral neck, we recommend consideration be given to concomitant restoration of the normal femoral head-neck offset to protect the osteochondral graft in the acetabulum, depending on its location. Despite this limitation, we demonstrate the feasibility of osteochondral allograft transplantation by MRI demonstrating good incorporation of the allograft into the surrounding host bone, and no radiographic progression of joint space narrowing in either patient at short-term follow-up.

Focal osteochondral defects of the acetabulum are uncommon. Our observations in these cases suggest osteochondral allograft transplantation may be an appropriate alternative to consider when treating osteochondral defects of the acetabulum in young and active patients. Although our patients had excellent results at short-term follow-up, it remains important to verify the long-term durability of osteochondral allograft transplantation in the hip joint.

References

  1. 1. Yen YM, Kocher MS. Chondral lesions of the hip: microfracture and chondroplasty. Sports Med Arthrosc. 2010; 18(2):83–89. doi: 10.1097/JSA.0b013e3181de1189 [CrossRef]
  2. 2. Buckwalter J, Mankin H. Articular cartilage: degeneration and osteoarthritis, repair, regeneration, and transplantation. Instr Course Lect. 1998; (47):487–504.
  3. 3. Meyers MH, Akeson W, Convery FR. Resurfacing of the knee with fresh osteochondral allograft. J Bone Joint Surg Am. 1989; 71(5):704–713.
  4. 4. Davidson PA, Rivenburgh DW, Dawson PE, Rozin R. Clinical, histologic, and radiographic outcomes of distal femoral resurfacing with hypothermically stored osteoarticular allografts [published online ahead of print March 9, 2007]. Am J Sports Med. 2007; 35(7):1082–1090. doi: 10.1177/0363546507299529 [CrossRef]
  5. 5. Jamali AA, Emmerson BC, Chung C, Convery FR, Bugbee WD. Fresh osteochondral allografts: results in the patellofemoral joint. Clin Orthop Relat Res. 2005; (437):176–185. doi: 10.1097/01.blo.0000165854.15579.85 [CrossRef]
  6. 6. Gross AE, Shasha N, Aubin P. Long-term followup of the use of fresh osteochondral allografts for posttraumatic knee defects. Clin Orthop Relat Res. 2005; (435):79–87. doi: 10.1097/01.blo.0000165845.21735.05 [CrossRef]
  7. 7. McCulloch PC, Kang RW, Sobhy MH, Hayden JK, Cole BJ. Prospective evaluation of prolonged fresh osteochondral allograft transplantation of the femoral condyle: minimum 2 year follow-up [Published online ahead of print January 27, 2007]. Am J Sports Med. 2007; 35(3):411–420. doi: 10.1177/0363546506295178 [CrossRef]
  8. 8. Emmerson BC, Görtz S, Jamali AA, Chung C, Amiel D, Bugbee WD. Fresh osteochondral allografting in the treatment of osteochondritis dissecans of the femoral condyle [published online ahead of print March 16, 2007]. Am J Sports Med. 2007; 35(6):907–914. doi: 10.1177/0363546507299932 [CrossRef]
  9. 9. Williams RJ, IIIRanawat AS, Potter HG, Carter T, Warren RF. Fresh stored allografts for the treatment of osteochondral defects of the knee. J Bone Joint Surg Am. 2007; 89(4):718–726. doi: 10.2106/JBJS.F.00625 [CrossRef]
  10. 10. Martin RL, Kelly BT, Philippon MJ. Evidence of validity for the hip outcome score. Arthroscopy. 2006; 22(12):1304–1311. doi: 10.1016/j.arthro.2006.07.027 [CrossRef]
  11. 11. Meyers MH. Resurfacing of the femoral head with fresh osteochondral allografts. Long-term results. Clin Orthop Relat Res. 1985; (197):111–114.
  12. 12. Evans KN, Providence BC. Case report: fresh-stored osteochondral allograft for treatment of osteochondritis dissecans the femoral head [published online ahead of print September 2, 2009]. Clin Orthop Relat Res. 2010; 468(2):613–8. doi: 10.1007/s11999-009-0997-1 [CrossRef]
  13. 13. Nousiainen MT, Sen MK, Mintz DN, et al. The use osteochondral allograft in the treatment of a severe femoral head fracture. J Orthop Trauma. 2010; 24:120–124. doi: 10.1097/BOT.0b013e3181b7eae7 [CrossRef]
  14. 14. Delloye C, Banse X, Brichard B, Docquier PL, Cornu O. Pelvic reconstruction with a structural pelvic allograft after resection of a malignant bone tumor. J Bone Joint Surg Am. 2007; 89(3):579–587. doi: 10.2106/JBJS.E.00943 [CrossRef]
  15. 15. Cole BJ. Expanding the indications for allografts in joint surgery. In: American Orthopaedic Society for Sports Medicine; Allograft Workshop 2007. Calgary, AB, Canada, 2007:49–58.
  16. 16. Li G, Park SE, DeFrate LE, et al. The cartilage thickness distribution in the tibiofemoral joint and its correlation with cartilage-to-cartilage contact. Clin Biomech. 2005; 20(7):736–744. doi: 10.1016/j.clinbiomech.2005.04.001 [CrossRef]
  17. 17. Wyler A, Bousson V, Bergot C, et al. Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements. Radiology. 2007; 242(2):441–449. doi: 10.1148/radiol.2422051393 [CrossRef]
  18. 18. Hangody L, Fules P. Autologous osteochondral mosaicplasty for the treatment of full-thickness defects of weight-bearing joints: ten years of experimental and clinical experience. J Bone Joint Surg Am. 2003; 85(Suppl 2):25–32.
  19. 19. Jakob RP, Franz T, Gautier E, Mainil-Varlet P. Autologous osteochondral grafting in the knee: indication, results, and reflections. Clin Orthop Relat Res. 2002; (401):170–184. doi: 10.1097/00003086-200208000-00020 [CrossRef]
  20. 20. Bastian JD, Büchler L, Meyer DC, Siebenrock KA, Keel MJ. Surgical hip dislocation for osteochondral transplantation as a salvage procedure for a femoral head impaction fracture. J Orthop Trauma. 2010; 24(12):e113–118. doi: 10.1097/BOT.0b013e3181dfbb52 [CrossRef]
  21. 21. Tibor LM, Sekiya JK. Differential diagnosis of pain around the hip joint [published online ahead of print August 28, 2008]. Arthroscopy. 2008; 24(12):1407–1421. doi: 10.1016/j.arthro.2008.06.019 [CrossRef]

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