osteochondritis dissecans of the knee management cover

osteochondritis dissecans of the knee: management

case presentation

A healthy, 13-year-old female presents with a 6 weeks history of anterior knee pain.  The patient describes pain over the tibial tubercle region that worsens with running and jumping.  It seems to be progressive and does seem to improve with rest and overnight.  She denies any locking, catching or instability.  She denies any swelling.  X-rays are ordered showing a 1 cm stable osteochondritis dissecans lesion over the medial femoral condyle.  An MRI is subsequently ordered showing edema noted over the tibial tubercle consistent with Osgood-Schlatter disease.  The OCD lesion had a stable articular surface without any underlying edema or signs of instability.  Which of the following is the most appropriate treatment?

A. Operative management, internal fixation
B. Operative management, OATS procedure
C. Operative management, tibial osteotomy
D. Nonoperative management

introduction

Management of  osteochondritis dissecans of the knee remains a controversial topic. The most recent practice guidelines by the American Academy of Orthopaedic Surgeons (AAOS) was unable to make any recommendations graded as ‘strong’ regarding treatment [1].  Treatment decisions are influenced on clinical symptoms, skeletal maturity and characteristics of the lesion (size, location and stability).  Skeletal maturity and lesion stability are generally considered the most important information for clinical decision-making [1].

nonoperative management

Depending on these factors, nonoperative or operative treatment may be appropriate.  Nonoperative treatment is well accepted for patients with open physes, stable lesions, or minimal symptoms. Duration is typically a minimum of 3 to 6 months followed by gradual return to activity. Protocols on activity modification, weight-bearing restriction, and immobilization vary.
Immediate cessation of athletics and impact activities is usually recommended if nonoperative management is pursued. Some providers prefer protected weight-bearing for minimizing compression across the lesion, while others have reported success with unloader bracing protecting the lesion.
Case OCD lesion knee with MRI and x-ray

Image 1: A 14-year-old girl who underwent internal fixation with bioabsorbable headless compression screws and proximal tibial medial opening-wedge osteotomy for treatment of an OCD lesion on the medial femoral condyle with associated varus deformity at the knee.  Adopted from [5].

Kocher et al. [2] has reported a protocol that is popular for many providers.  The first phase involves knee immobilization for four to six weeks with crutch-protected, partial weight-bearing gait. At the end of this period, the child should be pain-free and repeat radiographs should be obtained. If the patient is not pain free, then this phase is continued.

In phase 2 (normally weeks six to twelve), weight-bearing as tolerated is permitted without immobilization. A rehabilitation program is initiated emphasizing knee ROM and low-impact quadriceps and hamstring strengthening exercises. Sports and repetitive-impact activities are restricted.

If there are radiographic and clinical signs of healing at three to four months after the initial diagnosis, phase 3 is started. This phase includes supervised initiation of running, jumping and cutting sports-readiness activities. A gradual return to sports with increasing intensity is allowed in the absence of knee symptoms. An MRI is repeated in phase 3 to assess healing.

Wall et al. reported a series of patients with stable JOCD of the knee treated nonoperatively [3]. Treatment consisted of an initial six-week period of weight-bearing immobilization in a cast. If the lesion showed re-ossification on radiographs, casting was discontinued. If re-ossification was not present, the patients were allowed three to seven days out of the cast to regain ROM, followed by casting for an additional four to six weeks.

After casting, patients were placed in an unloader brace and restricted from running, jumping and sports. During this phase, patients were radiographed every six to eight weeks and activity was slowly advanced, as long as radiographs showed progression of healing. Return to full activity was allowed after complete re-ossification was demonstrated on radiographs. After six months of non-operative treatment, 31/47 lesions (66%) had progression towards healing and patients reported no pain [3].

Beyond a consensus that non-operative treatment should be used for at least three to six months in stable lesions, there is little agreement on which regimen is more effective. Future research in this area is required to compare different treatment protocols [4].

operative treatment

Surgery is primarily indicated for patients with unstable lesions, failed conservative treatment, or poor nomogram predictions. The technique depends on the lesion characteristics. Concomitant pathology, including limb malalignment and joint instability, may require surgical correction [5].

Subchondral drilling is well-established for stable lesions to stimulate influx of mesenchymal cells and growth factors [6]. Techniques include transarticular and retroarticular (transepiphyseal) drilling [7]. Retroarticular drilling avoids cartilage penetration but requires fluoroscopy. A systematic review concluded that there were comparable patient-oriented and radiographic outcomes [8].

Algorithm for treatment for Osteochondritis dissecans knee

Figure 2.  Previously proposed algorithm for treatment of OCD lesions of the knee.  Adopted form [4].

Principles for treating unstable salvageable lesions include articular surface restoration, fracture fixation, and vascular enhancement [9]. If accessible (trapdoor lesions), the fibrous tissue from base of the lesion and bony surface of the flap are debrided with a curette or arthroscopic shaver. If there is a resultant bone void, bone grafting from the proximal tibia or iliac crest is performed.  Fixation devices include headless, partially threaded, variable-pitch compression screws, and bioabsorbable implants. 

Each of the techniques or materials can have advantages and disadvantages.  Metal screws can provide excellent purchase to help in healing but are dependent on lesion quality and tissue composition (e.g., cartilaginous versus osseous), may need to be removed before full weight-bearing, and interfere with MRI assessment.

These concerns have led to the development of bioabsorbable implants. Bioabsorbable devices have been made from polyglycolic acid (PGA) or polylactic acid (PLA). PGA has a rapid degradation rate, reportedly absorbing in three months with high incidence of foreign body reactions [10]. PLA, which was later introduced in response to problems encountered with PGA devices, can take as long as six years to absorb and may place opposing cartilage at risk for damage by the implant [11].  Mixtures have also been used.  These can be associated with loosening, synovitis, and cyst formation [4].

Autogenous osteochondral plugs have recently been presented as a biologic alternative to the use of hardware. The plugs provide bone graft as well as fixation of the lesion. Three studies reported that biological fixation provided healing of the osteochondral fragment with promising results [12-14]. 

More recently, hybrid fixation has been proposed as an alternative method. Hybrid fixation allows preservation of the osteochondral fragment with unstable femoral condyle OCD, by combining mechanical (screws) and biological (osteochondral autograft transplantation surgery (OATS)) fixation [4].

Lesions may be unsalvageable because of substantial osteochondral fragmentation, subchondral necrosis, or cartilage degeneration.  When the progeny fragment has comminuted into multiple small fragments, incongruous with the donor site, or the articular cartilage is excessively deteriorated, primary fixation may not be the most viable option [15].

OCD knee drilling case

Image 3: An 11-year-old boy who underwent transarticular drilling for treatment of an OCD lesion in the medial femoral condyle of the left knee.  Adopted from [4].

Microfracture is indicated in patients with a localized small cartilage defect. However, in most OCD lesions this may not be possible as the subchondral bone is often absent. The OATS technique transfers both articular cartilage and subchondral bone from a non-weight-bearing area of the knee to the site of the defect and is most effective in lesions < 2.5 cm [16]. 

Gudas et al randomized 50 children to either microfracture or OATS for treatment of femoral condylar JOCD. At one year, both groups had good or excellent results in their functional and objective assessment, but at 4.2 years, the OATS group maintained an 83% good or excellent result, while the microfracture group dropped to 63%. Failure rates were 41% in the microfracture group and 0% in the OATS group, with an inverse relationship between defect size and outcome in the microfracture group, without a similar relationship in the OATS group [17].

For larger lesions, osteochondral allograft transplantation procedures may be used.  Autologous chondrocyte implantation (ACI) is a two-stage cellularly based autograft technique [18].  The first stage involves an arthroscopic biopsy from healthy cartilage in the non-weight-bearing region of the intercondylar notch. These cells are grown in vitro over four to six weeks, at which point the patient returns for implantation. During this procedure, the calcified cartilage is removed and the lesion is debrided to stable vertical walls [18].  Mithofer et al [19] reported 96% good to excellent outcomes at the mid-term in adolescent patients undergoing ACI for OCD. Similarly, 96% of patients also returned to high-impact sports and 60% returned to a level equal or higher than before their knee injury.

Summary

In summary, nonoperative treatment should be the first-line treatment for stable lesions. There are many proposed protocols but randomized trials are limited.  Surgical treatment for stable lesions with intact articular cartilage involves drilling the subchondral bone aiming to stimulate vascular ingrowth and subchondral bone healing. If the lesion is unstable, fixation is indicated. Every attempt should be made to retain the osteochondral fragment when possible. If fixation is not possible, there are multiple salvage techniques available.

CASE CONCLUSION

D. Treatment decisions are influenced on clinical symptoms, skeletal maturity and characteristics of the lesion (size, location and stability).  Skeletal maturity and lesion stability are generally considered the most important information for clinical decision-making.  A stable lesion that is less than 2.5 cm will most likely proceed with nonoperative management.  The symptoms described are most likely coming from Osgood-Schlatter disease and not the osteochondritis dissecans lesion.

– More Knee Pain: https://www.sportsmedreview.com/by-joint/knee/
– More on OCD Lesions at Wiki Sports Medicine: https://wikism.org/Osteochondral_Defect_Knee

References

  1. American Academy of Orthopedic Surgeons. Clinical practice guideline on the diagnosis and treatment of osteochondritis dissecans. Rosemont, IL: American Academy of Orthopedic Surgeons, 2010.
  2. Kocher MS, Tucker R, Ganley TJ, Flynn JM. Management of osteochondritis dissecans of the knee: current concepts review. Am J Sports Med 2006;34(7):1181–1191. doi: 10.1177/0363546506290127
  3. Wall EJ, Vourazeris J, Myer GD, et al. The healing potential of stable juvenile osteochondritis dissecans knee lesions. J Bone Joint Surg [Am] 2008;90(12):2655–2664. doi: 10.2106/JBJS.G.01103 
  4. Masquijo J, Kothari A. Juvenile osteochondritis dissecans (JOCD) of the knee: current concepts review. EFORT Open Rev. 2019 May 17;4(5):201-212. 
  5. Chau MM, Klimstra MA, Wise KL, Ellermann JM, Tóth F, Carlson CS, Nelson BJ, Tompkins MA. Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes. J Bone Joint Surg Am. 2021 Jun 16;103(12):1132-1151
  6. Heyworth BE, Edmonds EW, Murnaghan ML, Kocher MS. Drilling techniques for osteochondritis dissecans. Clin Sports Med 2014. April;33(2):305–12. Epub 2014 Feb 18.
  7. Lee CS, Larsen CG, Marchwiany DA, Chudik SC. Extra-articular, intraepiphyseal drilling for osteochondritis dissecans of the knee: characterization of a safe and reproducible surgical approach. Orthop J Sports Med 2019. February 28;7(2):2325967119830397
  8. Gunton MJ, Carey JL, Shaw CR, Murnaghan ML. Drilling juvenile osteochondritis dissecans: retro- or transarticular? Clin Orthop Relat Res 2013. April;471(4):1144–51
  9. Cahill B Treatment of juvenile osteochondritis dissecans and osteochondritis dissecans of the knee. Clin Sports Med 1985. April;4(2):367–84.
  10. Fridén T, Rydholm U. Severe aseptic synovitis of the knee after biodegradable internal fixation. A case report. Acta Orthop Scand 1992;63(1):94–97.
  11. Mainil-Varlet P, Rahn B, Gogolewski S. Long-term in vivo degradation and bone reaction to various polylactides. 1. One-year results. Biomaterials 1997;18(3):257–266.
  12. Berlet GC, Mascia A, Miniaci A. Treatment of unstable osteochondritis dissecans lesions of the knee using autogenous osteochondral grafts (mosaicplasty). Arthroscopy 1999;15(3):312–316.
  13. Sasaki K, Matsumoto T, Matsushita T, et al. Osteochondral autograft transplantation for juvenile osteochondritis dissecans of the knee: a series of twelve cases. Int Orthop 2012;36(11):2243–2248.
  14. Miura K, Ishibashi Y, Tsuda E, Sato H, Toh S. Results of arthroscopic fixation of osteochondritis dissecans lesion of the knee with cylindrical autogenous osteochondral plugs. Am J Sports Med 2007;35(2):216–222
  15. Polousky JD, Albright J. Salvage techniques in osteochondritis dissecans. Clin Sports Med 2014;33(2):321–333
  16. Hangody L, Füles 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-A(suppl 2):25–32. 
  17. Gudas R, Simonaityte R, Cekanauskas E, Tamosiūnas R. A prospective, randomized clinical study of osteochondral autologous transplantation versus microfracture for the treatment of osteochondritis dissecans in the knee joint in children. J Pediatr Orthop 2009;29(7):741–748.
  18. Minas T, Peterson L. Advanced techniques in autologous chondrocyte transplantation. Clin Sports Med 1999;18(1):13–44, v–vi.

Mithöfer K, Minas T, Peterson L, Yeon H, Micheli LJ. Functional outcome of knee articular cartilage repair in adolescent athletes. Am J Sports Med 2005;33(8):1147–1153.