Table 3.
Summary of results of included studies
| Author, year of publication | N | Follow-up rate | Participant characteristics at baseline | Association between AKP and PFOA | Other findings | Quality score (0-15) |
|---|---|---|---|---|---|---|
| Utting et al 2005 [18] | 234 (118 cases, 116 controls). |
Response rate 78% (cases 79%, controls 77%). |
Cases 90%F mean age at time of arthroplasty 67.3 years (range 44-87). Controls: 82%F mean age at time of arthroplasty 68.3 years (range 48-86). |
Crude OR = 4.4 (95%CI 1.8, 10.6) | Prior history of AKP (22% vs 6%), PF instability (14% vs 1%), and patella trauma (16% vs 6%) among cases. No difference in mean age at onset of AKP (18.1 vs 19.4 years). |
9 |
| Kannus et al 1999 [19] | 37 | 70% |
Based on 49 potentially eligible participants: 53% F Mean age 27 years (range 15-50). Mean duration of symptoms 16 months (SD 19). |
- | PFOA at follow-up (mean 6.6 years). On plain x-ray: mild 16%, moderate 0%, severe 3% On MRI: mild 11%, moderate 19%, severe 5%. Estimated annual risk of PFOA 2.9%. |
8 |
| Nimon et al 1998 [20] | 8 | 13% |
Based on 63 potentially eligible patients: 100%F Mean age 15.5 years (range 10-19). |
- | Plain x-rays "normal" on participants imaged at follow-up (mean 16 years). Estimated annual risk of PFOA 0%. |
8 |
| Imhoff & Boni 1989 [21] | 29 | 19% | 55%F Mean age at diagnosis 23 years (range 7-52). 11 had a history of knee trauma. |
- | PFOA at follow-up (mean 23 years): Small superior patellar osteophytes (31%), joint space narrowing/ ↑ osteophytes/subchondral sclerosis 10.3%, joint space obliteration/cystic changes 6.9%. Estimated annual risk of PFOA 2.1%. |
5 |
| Hvid et al 1981 [22] | 22 | 100% (?) | 60%F Mean age 27 years (range 14-44). Mean duration of symptoms 7.6 years (range 4-16). |
- | No arthrosis in any participant at follow-up (mean 5.7 years). Estimated annual risk of PFOA 0%. |
11 |
| Dexel et al 1980 [23] | 25 | 15% | 32%F Mean age 25 years (range 15-52). 5 had a history of post-traumatic patellar chondropathy. |
- | Moderate or severe changes consistent with PFOA at follow-up (mean 13 years) 12%. Estimated annual risk of PFOA 0.9%. |
5 |
| Karlson 1939 [24] | 35 | 31% |
Based on 71 potential eligible patients: 0%F 11% aged <20 years, 80% 20-29, 8% 30-59. |
- | "very slight" arthritis deformans at follow-up (mean 5.9 years) 20%. Estimated annual risk of PFOA 3.4%. |
3 |
AKP Anterior knee pain; F Female; OR Odds ratio; PF patellofemoral; PFOA Patellofemoral osteoarthritis; 95%CI 95 percent confidence interval