Harris (1969) reports outcomes of 39 mold arthroplasties for post-traumatic hip arthritis (acetabular fractures and dislocations) at MGH between 1945 and 1965. The paper simultaneously introduces a new 100-point hip function rating system designed to be more sensitive and broadly applicable than existing Larson and Shepherd systems. This instrument became the Harris Hip Score — the most widely used physician-administered hip outcome measure globally.
The HHS was not designed for total hip arthroplasty — it was built for young men with severe post-traumatic arthritis undergoing Smith-Petersen mold arthroplasty. Its heavy weighting toward pain and function reflects what drove those patients to surgery.
You need the score's structure cold for boards and for interpreting the literature. When a paper reports a mean postoperative HHS of 92, that is excellent by Harris's own thresholds. When it reports 78, that is fair. A result most patients and surgeons would not consider a success.
Know the deformity domain rule: all 4 deformity points are lost if the patient has a fixed flexion contracture >30°, fixed adduction >10°, fixed internal rotation >10°, or limb-length discrepancy >3.2 cm. Any single finding wipes the entire domain.
The HHS has a well-documented ceiling effect in primary THA populations. Patients cluster at the top, making it insensitive to differences between good and excellent outcomes. This is why modern trials pair the HHS with patient-reported measures (PROMIS, HOOS-Jr). The score is also examiner-administered, not patient-reported, which introduces bias when the surgeon scoring the result has a stake in it.
Harris (1969) reports outcomes of 39 mold arthroplasties for post-traumatic hip arthritis (acetabular fractures and dislocations) at MGH between 1945 and 1965. The paper simultaneously introduces a new 100-point hip function rating system designed to be more sensitive and broadly applicable than existing Larson and Shepherd systems. This instrument became the Harris Hip Score — the most widely used physician-administered hip outcome measure globally.
The HHS was not designed for total hip arthroplasty — it was built for young men with severe post-traumatic arthritis undergoing Smith-Petersen mold arthroplasty. Its heavy weighting toward pain and function reflects what drove those patients to surgery.
You need the score's structure cold for boards and for interpreting the literature. When a paper reports a mean postoperative HHS of 92, that is excellent by Harris's own thresholds. When it reports 78, that is fair. A result most patients and surgeons would not consider a success.
Know the deformity domain rule: all 4 deformity points are lost if the patient has a fixed flexion contracture >30°, fixed adduction >10°, fixed internal rotation >10°, or limb-length discrepancy >3.2 cm. Any single finding wipes the entire domain.
The HHS has a well-documented ceiling effect in primary THA populations. Patients cluster at the top, making it insensitive to differences between good and excellent outcomes. This is why modern trials pair the HHS with patient-reported measures (PROMIS, HOOS-Jr). The score is also examiner-administered, not patient-reported, which introduces bias when the surgeon scoring the result has a stake in it.