Matta's 1986 retrospective study examined 204 acetabular fractures, with clinical follow-up on 64 displaced fractures treated by open or closed methods. It asks: how much displacement is acceptable, and how much intact dome is needed to avoid surgery? The paper establishes the roof arc measurement system and the 3 mm reduction threshold as the central decision-making framework for acetabular fracture management.
Before this paper, the decision to operate on an acetabular fracture rested on qualitative assessments of dome integrity with no agreed quantitative standard. Rowe and Lowell described the weight-bearing dome in general anatomic terms, but provided no measurement framework a surgeon could apply at the light box.
Matta's roof arc system changes that. When you see a displaced acetabular fracture, pull the AP and both obliques and measure all three arcs. If any arc falls below threshold — medial 30°, anterior 40°, posterior 50° — or if the head subluxes out of traction, the dome is insufficient and surgery is indicated.
The 3 mm reduction threshold is the number to carry into the OR. Achieving it with congruent dome contact yields 91% good/excellent outcomes. Failing to achieve it — whether by traction or inadequate open technique — predicts a poor result regardless of how the case was approached.
The high complication rates in this series also carry a teaching: acetabular surgery without Letournel's systematic approach to fracture classification and approach selection produces preventable failures. This paper directly preceded the adoption of Letournel's techniques in North America and set the evidence basis for subspecialty referral of complex acetabular fractures.
Matta's 1986 retrospective study examined 204 acetabular fractures, with clinical follow-up on 64 displaced fractures treated by open or closed methods. It asks: how much displacement is acceptable, and how much intact dome is needed to avoid surgery? The paper establishes the roof arc measurement system and the 3 mm reduction threshold as the central decision-making framework for acetabular fracture management.
Before this paper, the decision to operate on an acetabular fracture rested on qualitative assessments of dome integrity with no agreed quantitative standard. Rowe and Lowell described the weight-bearing dome in general anatomic terms, but provided no measurement framework a surgeon could apply at the light box.
Matta's roof arc system changes that. When you see a displaced acetabular fracture, pull the AP and both obliques and measure all three arcs. If any arc falls below threshold — medial 30°, anterior 40°, posterior 50° — or if the head subluxes out of traction, the dome is insufficient and surgery is indicated.
The 3 mm reduction threshold is the number to carry into the OR. Achieving it with congruent dome contact yields 91% good/excellent outcomes. Failing to achieve it — whether by traction or inadequate open technique — predicts a poor result regardless of how the case was approached.
The high complication rates in this series also carry a teaching: acetabular surgery without Letournel's systematic approach to fracture classification and approach selection produces preventable failures. This paper directly preceded the adoption of Letournel's techniques in North America and set the evidence basis for subspecialty referral of complex acetabular fractures.