Introduction

Joint preservation is a conceptual approach to arthritis treatment using various surgical and nonsurgical modalities in a patient-specific manner. The cornerstone of joint preservation is taking into account the severity of arthritis symptoms, degree of disease, and patient expectations while developing this multimodal approach to treatment. While there is no fixed algorithm for joint preservation, it typically begins with nonoperative treatments. Oral analgesics, nonsteroidal anti-inflammatory medications, and physical therapy are known to alleviate the discomfort associated with unicompartmental arthritic disease. Unloader bracing is a good option for unicompartmental disease in the more active and athletic patient. Injection treatments with corticosteroid solutions and viscosupplementation have also been shown to be effective in alleviating pain and improving knee function. However, there are certain situations when nonarthroplasty procedures are indicated and may provide more reliable relief of pain and dysfunction than continued nonoperative treatments. These techniques are typically best suited for younger, active patients with unicompartmental disease whose age and activity level contraindicate them for a unicompartmental arthroplasty. The common nonarthroplasty options for unicompartmental disease include arthroscopic débridement, cartilage restorative techniques, high tibial osteotomy, and distal femoral osteotomy.

Arthroscopic Débridement

Mechanical symptoms associated with meniscal or chondral lesions are the clearest indication for arthroscopic débridement. However, patient expectations need to be clearly defined, and patients should be cautioned that a significant portion of their knee pain might be attributed to the existing arthritis. Multiple authors have shown improvement in knee rating score, improved knee function, decreased anti-inflammatory use, and high patient satisfaction in osteoarthritic knees treated with arthroscopic lavage and débridement.^1–4 Steadman et al.’s systematic arthroscopic approach to the degenerative knee included the expansion of joint space through the release of joint contractures, removal of loose bodies, limited chondroplasty, meniscectomy of unstable tears, thermal ablation of synovitis, and excision of osteophytes blocking full extension.⁴ Their published results on a consecutive series of patients with severe arthritis who underwent the procedure showed that greater than 70% of them had significant gains in knee function scores, satisfaction, and delay of arthroplasty at a minimum of 3 years postoperatively.⁴

The most cited predictors of failure of arthroscopic intervention include malalignment greater than 5°, age greater than 60, persistent symptoms greater than 1 year, history of prior surgery, and joint space less than 2 mm.^5–9 Steadman et al. added the presence of “kissing” grade 4 lesions and severity of joint contracture as additional independent predictors of failure. The preoperative presence of a symptomatic mechanical lesion seems to be the most reproducible predictor of success from arthroscopic débridement. Multiple authors have shown persistent symptomatic benefit in patients with combined meniscal pathology and degenerative changes treated with partial meniscectomy, but better results are seen if the meniscal component is acute rather than degenerative.^9–13

In contrast to the multiple reports of success with arthroscopic débridement in osteoarthritis, Moseley et al. and Kirkley et al. demonstrated equal efficacy between a focused physical therapy program and arthroscopic débridement.^14,15 Moseley et al. also reported similar outcomes with a “sham-operation” highlighting the power of the placebo effect.¹⁴ Their interpretation of these results has caused many clinicians to question the utility of arthroscopy in the setting of osteoarthritis.^14,15 However, some surgeons criticize these studies for lacking a specific patient cohort with arthritis but predominating mechanical symptoms. The randomized nature of these two studies does demonstrate that the blind application of arthroscopic débridement to osteoarthritis is unlikely to produce successful outcomes greater than nonsurgical treatments and highlights the importance of critically analyzing the patient’s symptomatology and applying strict patient selection criteria.

While the use of arthroscopy in the setting of osteoarthritis remains controversial, success from arthroscopic débridement seems to be linked to the predominance of mechanical symptoms, younger age, and neutral alignment. Steadman attributes his success with arthroscopy of degenerative disease in part to the treatment of the associated synovitis and arthrofibrosis. The patient’s expectations and desire to remain active are intangibles that are difficult to quantify but should undoubtedly play a roll in the decision to offer arthroscopic débridement in the setting of osteoarthritis.

Cartilage Restoration

There are multiple, well-studied restorative options for the treatment of acute full-thickness articular cartilage defects. The most common options include microfracture, osteochondral transfer, and autologous chondrocyte transplantation. Despite the continued debate surrounding the appropriate indications and expected longevity for these procedures, one can expect good to excellent results when these restorative options are applied appropriately to the acute full-thickness lesion. On the contrary, most attempts at cartilage restoration will fail in the setting of significant degenerative disease. It is thought that the osteoarthritic environment is not conducive to these techniques and that either the cartilage at the periphery of the degenerative lesion is too thin to contain the repair or the surrounding cartilage will continue to degenerate. In a review of microfracture in the degenerative knee, there were significant gains in Lysholm scores but the improvement in function was less when compared to their “traumatic” counterpart (Fig. 8–1).¹⁶ Larger lesions, older patients, those lesions defined as “degenerative” rather than “traumatic,” and bipolar lesions all were associated with less improvement in knee function scores.¹⁶ Andres et al.’s review of osteochondral autograft transplantation demonstrated significantly greater improvements in the pain relief and function of the “isolated lesion” group compared to the “degenerative lesion” group.¹⁷ In a diverse group of patients treated with autologous chondrocyte implantation, McNickle et al. found that age was an independent predictor of postoperative Lysholm score, with less improvement in older patients.¹⁸

Figure 8–1 Degenerative chondral defects before microfracture (A) and after microfracture (B).

(Photos courtesy of Dr. William Sterett, Steadman-Hawkins Clinic, Vail, CO.)