Subchondral Calcium Phosphate is Ineffective for Bone Marrow Edema Lesions in Adults With Advanced Osteoarthritis

Abstract

Background Injury to subchondral bone is associated with knee pain and osteoarthritis (OA). A percutaneous calcium phosphate injection is a novel approach in which subchondral bone marrow edema lesions are percutaneously injected with calcium phosphate. In theory, calcium phosphate provides structural support while it is gradually replaced by bone. However, little clinical evidence supports the efficacy of percutaneous calcium phosphate injections. Questions/purposes We asked: (1) Does percutaneous calcium phosphate injection improve validated patient-reported outcome measures? (2) What proportion of patients experience failure of treatment (defined as a low score on the Tegner Lysholm Knee Scoring Scale)? (3) Is there a relationship between outcome and age, sex, BMI, and preoperative grade of OA? Methods Between September 2012 and January 2014, we treated 33 patients with percutaneous calcium phosphate injections. Twenty-five satisfied our study inclusion criteria; of those, three patients were lost to followup and 22 (88%; 13 men, nine women) with a median age of 53.5 years (range, 38-70 years) were available for retrospective chart review and telephone evaluation at a minimum of 6 months (median, 12 months; range, 6-24 months). Our general indications for this procedure were the presence of subchondral bone marrow edema lesions observed on MR images involving weightbearing regions of the knee associated with localized pain on weightbearing and palpation and failure to respond to conservative therapy ([ 3 months). Patients with pain secondary to extensive nondegenerative meniscal tears with a flipped displaced component at the level of bone marrow edema lesions, or with mechanical axis deviation greater than 8°were excluded. All patients had Grades III or IV chondral lesions (modified Outerbridge grading system for chondromalacia) overlying MRI-identified subchondral bone marrow edema lesions. Percutaneous calcium phosphate injection was performed on the medial tibial condyle (15 patients), the medial femoral condyle (five patients), and the lateral femoral condyle (two patients). Concomitant partial meniscectomy was performed in 18 patients. Preoperative and postoperative scores from the Knee Injury and Arthritis Outcome Score (KOOS) and the Tegner Lysholm Knee Scoring Scale were analyzed. Results For patients available for followup, the outcome scores improved after treatment. The KOOS improved from a mean of 39.5 ± 21.8 to 71.3 ± 23 (95% CI, 18.6-45.2; p \ 0.001) and the Tegner and Lysholm score from 48 ± 15.1 to 77.5 ± 20.6 (95% CI, 18.8-40.2; p \ 0.001).

Cartilage damage: a review of surgical repair options and outcomes

“…While subchondroplasty studies have revealed promising results for this procedure, the limits to which this procedure can provide patients with pain relief and improved function are still being determined. Chatterjuu et al, provided evidence that injectable CaP into subchondral BML did not reliably provide pain relief and/ or improved function to patients with advanced knee OA [80]. This study demonstrates that 31.8% of patients, out of 22 patient study group, with grade III or IV cartilage defects experienced a poor surgical outcome which was measured post-operatively with KOOS, Tegner and Lysholm scores [80].…”

“…Chatterjuu et al, provided evidence that injectable CaP into subchondral BML did not reliably provide pain relief and/ or improved function to patients with advanced knee OA [80]. This study demonstrates that 31.8% of patients, out of 22 patient study group, with grade III or IV cartilage defects experienced a poor surgical outcome which was measured post-operatively with KOOS, Tegner and Lysholm scores [80]. The 6-year prospective nonrandomized study of subchondroplasty effectiveness published by Cohen and Skarkey reported durable improvement of pain scores and symptom/function scores from patients status post knee subchondroplasty via arthroscopy [77].…”

Letter to the Editor: Subchondral Calcium Phosphate is Ineffective for Bone Marrow Edema Lesions in Adults with Advanced Osteoarthritis

“…To the editor, I have read the study by Chatterjee et al [2] with great interest. The authors presented results of an initial case series of patients with osteoarthritis and bone marrow edema treated with a novel percutaneous calcium phosphate (CaP) injection technique.…”

Enhanced Subchondroplasty Treatment for Post‐Traumatic Cartilage and Subchondral Bone Marrow Lesions in a Canine Model

“…While SCP has reported clinical benefits in treating subchondral bone pathology and can be considered an orthobiologic, it has been associated with significant morbidity when used at higher volumes, and alone, does not fully address the current gap in treatment . As such, combination therapy to include other orthobiologics with CaP bone void filler may be beneficial.…”